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Road Safety - Science topic

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Accidents involving motorcycles are responsible for over 50% of open fractures of the tibia and can be associated with other lesions and the victims, in the vast majority, are youth and young adult (Brazil epidemiological data). What preventive measures could be taken to reduce this type of accident?
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Dear Dr. Nelson Elias ,
I suggest you to have a look at the following, interesting reference:
- Motorcycle Safety
My best regards, Amir Beketov.
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With the increasing number of push and electric powered bicyclists and the increased uptake in micro-mobility devices such as electric scooters there is a need on many corridor for either a third speed corridor (for those doing 15 to 30km/h) or the operating speeds on the roadway or footpath/sidewalks need to lowered through speeds limits.
Q1 Has anyone had experience with setting footpath/sidewalk speed limits?
Q2 Is there any experience dropping speed limits to 30km/h on roads because of micro-mobility demands? - in conjunction often with bicycle boulevards
Q3 What changes need to be made to footpaths to make them micro-mobility/bicycle friendly (e.g. around heights of fencing etc)?
Q4 Has anyone come up with a suitable name for this third lane? Also possibly changing the name of footpaths - other than shared paths!
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Dear Dr. Shane Turner ,
I suggest you to have a look at the following, interesting reference:
My best regards, Amir Beketov.
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Road safety topics
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I suggest you to have a look at the following, interesting topics:
- Investigations of the influence of the urban road pavement roughness on movement of vehicles;
- Study of the impact of bus stops on city roads and streets on traffic flow and traffic safety;
- Study of the influence of transport and maintenance indicators of road surface of urban streets on traffic safety;
- Study of methods for assessing the quality of skid resistance of urban road surfaces.
My best regards, Amir Beketov.
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From Civil Engineering point of view, for the protection of community in society and workers in construction industry.
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That is a good question.
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I have one independent variable (gender) and five different dependent variables which are the score of five driving tasks. That is, if the driver does not perform any error while performing those tasks then he/she got 0 (no errors). However, when the driver does not manage to perform any of those tasks, 1, 2, or 3 are assigned (not properly performing some tasks means a danguras situation and that's why we assigned 2 to it).
I did use t-test/Mann-Whitney test to compare how each group perform each task.
Now, I would like to compare the scores of those driving taks for each group to know which driving tasks are more difficult than others for each group.
And, I would like to know which group should we focus on for better road safety (a group with fewer dangours errors, I guess).
Any suggestions?
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You should do a normality test and see if it is normally distributed or not. If it is normally distributed, then you can go ahead with parametric test to compare their mean. But if it is not normally distributed, then you can choose the non-parametric test. Unless or until you haven't mentioned your hypothesis, i cant suggest any test name. If you can state your hypothesis then I can suggest you the best test for your data.
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What is distress? Why the distress is a problem?Typical Causes of the distress?
Probable solution to the Problem in Pakistan ?
Discuss Solution to Potholes in Pakistan.
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Pavement distress particularly a road with asphalt concrete wearing course is coursed by heavy loading particularly at humps and bumps. It is manifested in form of rutting of road or excessive bleeding (too much asphalt on the top)
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Hi,
please help me with this question
I've been trying to model three-layer pavements (one rigid and one flexible) in Canada and I'm quite new to the design of pavements. My problem is the input. Do you have any suggestions as to where I can find the input data for pavements in Canada? I've been navigating the LTPP website, but it seems the data are not complete for the pavements. For instance, for one particular pavement, say SHRP_ID 0901, the input data are complete for all the layers but not for the Base Layer.
Thank you so much in advance!
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To model pavements with three layers (one rigid and one flexible) in Canada, it is necessary to collect this information from the design offices responsible for diagnosing and prospecting pavements affected by deterioration.
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I have a project on the impact of speed cameras on traffic flow and road safety performance in urban areas
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I would say it depends. Countries where speed enforcement using video camera is common, drivers may slow down. However, developing countries like India where speed enforcement is lagging, we didn’t observe any influence.
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I am looking for guidance, white papers and scholarly articles about road diets on an arterial street with an annual average daily traffic (AADT) above 45,000 and a peak hour volumes of 4,000 and greater.
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Ah, I see - based on your original question I was going to recommend against a road diet for your case, but it seems like it's been done and your topic makes sense. I know FHWA has a good series of case studies: https://safety.fhwa.dot.gov/road_diets/case_studies/
The case studies acknowledge the trade-offs with some road diet projects, often congestion, delays, or increased accidents of a certain category. I've been investigating relationships of capacity and demand, so the Highway Capacity Manual might have some notes as well. It seems that the road was already at capacity, so reducing capacity wouldn't have been recommended unless the City also invested in alternate modes of transportation, new routes, or other ways to mitigate.
Interested to hear what you find on this.
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Does anyone know any criticism of systems theory and approaches, and point me to supporting references? I have a draft paper on an assessment of road safety strategies, based on systems criteria. But one of the reviewers raised an interesting question; “The conclusions, while good, could be expanded by describing the limitations and complexities of systems work.”
Could you let me know if you can suggest any literature that could inform this question.
Thanks for any help.
Regards, Brett
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wow, interesting question. My first suggestion would be to look at Hari Tsoukas' critique of critical systems thinking. He refers to a paper of Mike Jackson in systems practice (now called systemic practice and action research). As far as I remember people criticise a so called lack of rigour leading to fall into theoretical and methodological incommensurability. Perhaps because of this, John Mingers has developed a view of systems thinking based on critical realism. Gerald Midgley has criticised the work of Jackson by arguing that methodological pluralism in frameworks like Total Systems Intervention or TSI needs to be more dynamic and flexible, following the complexities of a situation. He also raised the issue of how ethical issues related to seeking improvements are to be dealt with, suggesting that improvement needs to be locally rather than normatively defined by stakeholders. Complexity theorists would follow this apparent lack of flexibility to argue that it is complexity, not systems thinking, which could then provide for such flexibility. However they could also be criticised by establishing some 'normative' principles as to how complex social systems or situations are to 'behave'. I guess this would be my answer. Good luck with your paper!
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I am doing a qualitative study on Road Safety Involving various stakeholders. I have done indepth interviews with them. I need a standard proforma for writing the qualitative study. Can anyone suggest me the guidelines for qualitative research.
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The following sources may further help, particularly: the analytic procedure/guidelines/reporting of qualitative data analysis (see: Spiggle, 1994, pp. 496-500; Perry, 1998, pp. 33-37; Ritchie and Lewis, 2003, pp. 219-293).
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  • Braun, V. and Clarke, V. (2012) Thematic analysis, in Cooper, H., Camic, P.M., Long, D.L., Panter, A.T., Rindskopf, D. and Sher, K.J. (eds.) APA handbook of research methods in psychology, Vol 2: Research designs: Quantitative, qualitative, neuropsychological, and biological. Washington, DC: American Psychological Association, pp. 57-71.
  • · Chenail, R. J. (1995) Presenting Qualitative Data, The Qualitative Report, 2, 3, pp. 1-8.
  • · Miles, M. B. and Huberman, A. M. (1994) Qualitative Data Analysis: An Expanded Sourcebook. 2nd edn. CA: Sage: Thousand Oaks.
  • · Perry, C. (1998) A structured approach to presenting phd theses: notes for candidates and their supervisors, Australasian Marketing Journal, 6, 1, pp. 1-57.
  • · Ritchie, J. and Lewis, J. (2003) Qualitative research practice: A guide for social science students and researchers. London: SAGE Publications.
  • · Spiggle, S. (1994) Analysis and interpretation of qualitative data in consumer research, Journal of consumer research, 21, 3, pp. 491-503.
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I'm looking for definitive references on road infrastructure, traffic and operational crash risk factors for urban local roads. By local, I mean non-arterials (access streets, collectors) and low-order arterials (some call them distributors). Generally, the roads are in the 50 - 20,000 vpd AADT range, although there would be rare exceptions.
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Please refer to the following article from Accident Analysis & Prevention Journal by Omranian et al.:
Exploring rainfall impacts on the crash risk on Texas roadways: a crash-based matched-pairs analysis approach
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I want to establish the relationship between the accident rate m such features as gross domestic product, the auto industry, the number of inhabitants, the density of the road network, etc.
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we all have got great information. Thank you for asking such an interesting question.
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Asphalt roads can be damaged due to the effects of rainfall due to moisture infiltration, coupled with traffic loads. In areas where asphalt roads are laid especially rural areas where there are animal farms nearby, and cattle drives are common on the roads there is a very high chance that there is dung on the road and it is not cleared for a long time.
What are the effects on the road surface besides causing a runoff with high nutrient content to enter the waterways and causing an odour nuisance?
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laboratory testing is required to investigate the effects. Anyway, chemicals have bad effects on asphalt mixtures. Some chemicals can cause stripping which lead to deterioration.
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Can someone give me information of a capacity, geometry and safety of an Unsignalized U-turns. Thanks
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TIA comes with the legal background. Therefore it has been allowed normalize traffic level for all. But there are significant road segments that cannot allow the legal level.
If there any article journals related this please let me know. I like to make a framework for my study. therefore I need the base that other localities use.
Thank you,
Dilshan
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Good answer by Kundan.
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My colleagues and I are exploring to what extend Safe System / Vision Zero objective of minimising death and serious injury can be supported by modal shift.
For example, do you know of reputable studies correlating change in severe injuries with change in percentages of trips (or VKT) taken by public transport, bicycle, motorcycle or walking? What about user-specific outcomes, such as changes in pedestrian or cyclist safety with changes in proportion of travel? (...please no research on health benefits of cycling, well covered)
Australian Road Research Board have carried out past studies reviewing the subject and providing some high-level modelling. I am interested in some more in-depth studies providing newer and more robust relationships. Any trusted references will be greatly appreciated.
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Hi Chris,
I'm sorry I can't answer your question directly.
You might have already made coarse assessments based on transport models (e.g. 4 step). The safety consequences could be estimated from the changes in the amount of travel by each mode factored by crash rates per passenger or vehicle km travelled, and severities.
Unfortunately, the Safe Systems framework is too narrow to take account of the types of system changes you mention because it's beyond safe drivers, vehicles, roads and speeds.
Interestingly, WAs Towards Zero road safety strategy mentions the issue.
It's timely you asked though, because I've just finished a PhD which extends the normal narrow range of components and policy tools, and adds other elements to achieve best practice.
All of this has been known to other hazardous industries where
safety is critical, but road safety is stuck in a 90 year old simplistic paradigm.
Have a look via the Curtin Uni link and contact me at P7safety@gmail.com if you'd like to talk more.
Claes Tingvall, Paul Salmon, Ian Johnston and others have been complementary, although I don't have high hopes the conventional road safety industry will pick it up quickly.
I have also been talking to Peter Damen, about an ARRB webinar and a road safety project he's working o developing.
Best regards to all at ARRB, although there's probably not many who remember me from 1990!
Brett Hughes, Curtin Uni & DoT WA
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The specific number of roundabouts (on the unit of territory, population, length of roads) affects to road safety. Where can I see publications wich assess the impact of the number of roundabouts to road safety indicators? Or maybe there are such statistics for different countries?
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Hi Sergei, interesting question... Some time ago, I was also thinking of it. One could expect that "traditional roundabout countries" (such as the Netherlands, UK, Nordic countries) have higher level of safety. But you cannot assign this fact only to the number of roundabouts - it is rather a consequence of several factors, related not only to safe infrastructure, but also safety culture, behaviour, etc. - while all these elements are likely to be interrelated :-) But if you plan such analysis, I can give you estimate of number of Czech roundabouts - approx. 1200 :-)
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Hi, I was working on TRANSCAD and had confusions about creating the link O-D matrix for the larger networks based on the data obtained from the trip tables. I wanted to work on the Chicago Regional Network and I downloaded the trip tables from (http://www.bgu.ac.il/~bargera/tntp/). But somehow I am unable to make O-D matrix for the network. Any help would be appreciated.
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Thank you all for your answers. I appreciate your help.
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not only on speeds but also on travel times,route choices, model split on the level of traffic operations,road safety, and air pollution.
any relevant answer or materials to read will be very helpful to me.
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Sensor controlled traffic calming devices can be explored. They can use RFID based data to identify the emergency response vehicles.
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Dear fellow researchers,
I'm looking for the best method that is available to allocate/distribute funding for road safety management which would cover aspects such as engineering, enforcement, education & emergency response plan. Perhaps maybe someone can share their experiences/knowledges regarding this matter. Thanks in advance.
Regards,
ZARULAZAM EUSOFE
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The Chilean traffic signs standard recommends criteria for advisory speed and to place chevrons, but have no criteria for warning sings in sharp curves and how should be placed in roads with advisory speeds signs.
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I would recommend you use the same standard and rules used in your country to establish warning and traffic signs,  this is because although there is a standard many countries have theirs. Place the clearly stated sign at a distance and location where users would easily see it. 
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Does anyone know of any paper or research work related to the efectiveness of reducing the road wide within urban areas with the purpose of reducing speed and increasing safety? Thank you!
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You can explore the attached paper
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 From where can I get the database of the 100-Car naturalistic driving study ? Is it open ? Thank you in advance. 
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Check this site - https://insight.shrp2nds.us/
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For a new research project dealing with the safety of young cyclists, I am looking for publications or in-depth studies related to bicycle accidents of children aged between 8 and 14 years. Any hints to publications or other material would be appreciated.
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You can find some statistics when scan data base by age category: www.sewik.pl - polish database of accidents.
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In my activity within ABRAM (Autonomous BRAking for Motorcycles) project, I am trying to evaluate the potential benefits of an autonomous emergency braking system applied to motorcycles (also known as MAEB). Currently the potential benefits are expressed in terms of impact speed reduction.
Common sense suggests that a reduction in the impact speed may lead to a reduction in the severity of the crash outcomes. However, only a proof of a correlation between some crash parameters and injury outcomes would provide the fundamental support for assessing the potential benefits of MAEB.
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The linear correlation between motorcycle crash speed, crash speed squared (as a measure of KE) and various measures of injury severity (ISS, AISmax, Brain AISmax, etc.) runs in the neighborhood of .25 - .35.  This was true for Hurt study, Thailand study and MAIDS data.   Terry Smith's 2009 MAIDS paper showed a significant correlation of precrash (running) speed and injury severity but not crash speed.  
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My research study is focused on MOVES application to compare different type of intersection.
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Your question is not clear.
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I am interested in finding out details of road classification, hierarchy and design standards in Egypt. I would be grateful for any help or suggestions.
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Hallo Amjad, thanks for your message. I will add a page to my "road design standards" publication on Egypt. (This document already has a page on Iraq, but it may be out of date). Could you give me the titles of the 10 documents in Arabic? A copy of the one which deals with geometric design would be very helpful. My email is roadnotes2@gmail.com
Regards,
Robert
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Essentially, this relates to the mathematical problem of naturally poor correlation between low value continuous values (e.g. 0.003) with discrete values (0, 1, 2, etc). Has anyone come up with a workable solution to this in road safety?
I attach a map of local road crashes in parts of Melbourne, Australia, to demonstrate. The local roads (within the squares defined by arterials) have hardly any crashes. Models come up with low values no matter how good the model is. Poor correlation/model fit is guaranteed. Solution?
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Amir, big thanks for a very comprehensive answer. These are all techniques we considered or used at one time or another. i think Markov Switching models is something I'll look into more closely. 
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What is the relationship between knowledge in road safety and attitude towards road safety? Do respondents' age, sex, and socio-economic status moderate the relationship between knowledge of and attitude towards road safety? Empirical studies or literature on the above relationship is sought.
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Thank you, Dr Weerasekera. I will read and get back to you if I have comments
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Could you share with me this documents to compare characteristics like classification (primary, secondary, etc.), road width, lane width, separators, sidewalks dimensions, etc, with the real conditions of the roads in my city?
Thanks for your help!
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HI, if this is still an active question for you try the excellent answers and references I received for my recent question on urban local road safety. Most of the answers related to urban road safety in general.  
Very roughly: intersections and their design, land use, road standards, pedestrian movements.
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For long term trend of the number of crashes in a country, the weather conditions (long hard winter, warm spring and/or autumn) definitely are relevant.
Besides this, I have read about the relevance of the state of the economy as a further determinant of a rise or decrease of crashes several times. But the evidence always was from the US. I am curious if there is European evidence available, also.
I anybody aware of research from Europe, dealing with the influence of the weather and economic indicators on road crashes?
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In my country road safety information campaigns have not been used as a tool to reduce road accidents. Therefore, I assume that such a measure will have a good effect. However, we have experience in the development of such information campaigns. Where can I read the literature on the development of information campaigns, about the content, effectiveness evaluation, etc.
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According to my personal experience just because I worked in the past as a journalist for a specific campaign about road safety, I studied a bit the subject.
The client was a very relevant Italian PA with a consistent budget.
We share with those guys a panel of ideas and then they developed  a specific capaign utilizing an inhouse company.
The final result was to differentiate  the campaign through different medias .
They chose 3 different channel because it was in the late '90 during wich the social media had practically no existence.
So we proposed to select TV, radio and newspaper (divided in two groups, ie generalizated and specialized. The difference was to considered specialized if dedicated to a target focus of one scientific discipline.  So, for example, a financial newspaper was considered specialized instead a monthly journal for describing new and old cars was considered generalized).
In TV and in the radio the choice was to advertise in some particular hours like 6.00- 8.00 am and 6.00- 9.00 pm.
The message of 30'' or 1' was to describe what happened before an accident with deaths in wich, e. g., a child ask to his father: "dad, why did you decide to use your mobile phonewhen I say do not? " or a wife taking with her husband " you were in late but I didn't expect for dinner on time. I knew that were snowing. I told your on the phoneymoon be fore your leave the work". Others were about the the abuse of alcohol or drugs and even the cigarettes (the last was stopped by some tobacco lobby).
For specialized newspapers  we proposed to show inphograph about stats of accidents, number of deaths and serious  injuries with historic trends ( hoping they showed an improvement)
 For generalizated newspaper the message was with pictograms showing images of serious casualties and accidents.
Hoping to be a little bit useful. 
Luca
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I am aware of several methods/tools for measuring the ease with which a pedestrian can traverse urban environment. While they make good sense, none of them is based on any traceable research references. Please let me know if you are aware of such 'walkability' assessment methods which have solid basis in empirical evidence. Regards.
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Dear Chris, 
Thank you for your question, and for the fruitful discussion about this topic.
I suggest you to have a look at the Irvine Minnesota Inventory, which is a standard measure of the walkability degree of pedestrian facilities in terms of both comfort and safety (e.g., street connectivity, quality of sidewalks, signages).
If you are looking for a short questionnaire, I suggest you to have a look at the "Walkability Checklist: How walkable is your community" from the US Civil Trasportation Department.
Regards, Andrea
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Hello,
I have evaluated visibility level of drivers between two poles at the distance of 80 meters from the driver (having both road lighting and car headlight) using Adrian model. However, VL values are very small, compared to the French standard (VL>7), they are around 1. Could you please guide me about that. Thanks a lot in advance.
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Douglas, is this the report you mentioned for TxDOT?
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I am seeking information in regards to a new research project I am undertaking. It is an International and National (NZ) review of the available literature on ‘alternative interventions for youth traffic offenders’. Youth in our project covers those between the ages of 14-19 years of age. I am seeking information on interventions that have been proven to have a more positive impact on both reoffending and road safety than the traditional sanctions of custodial sentences, fines and licence demerit points. I will be reviewing information that covers three key areas:
·         Graduated Driver Licence System (GDLS) breaches and Unlicensed Driving
·         Drink/drug driving
·         Other offending (Speed, careless/reckless driving and restraints)
If you are able to furnish me with any information regarding the above or point me to any resources where such information may be available or put me in contact with anyone you believe would be of help in such matters I would be extremely grateful. Kind Regards,
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Dear Gerald and Jose
You are not really surprised, are you? This phenomenon is illustrated by the following example (cited from http://economictimes.indiatimes.com/definition/moral-hazard):
"You have not insured your house from any future damages. It implies that a loss will be completely borne by you at the time of a mishappening [sic] like fire or burglary. Hence you will show extra care and attentiveness. You will install high tech burglar alarms and hire watchmen to avoid any unforeseen event.
But if your house is insured for its full value, then if anything happens you do not really lose anything. Therefore, you have less incentive to protect against any mishappening. In this case, the insurance firm bears the losses and the problem of moral hazard arises."
Moral hazard, as the reaction to insurance is called, has been mentioned many times in recent years in discussions in the United States about problems that might arise (extra burden on the provision of medical assistance) as a result of state-funded medical insurance. A Swedish study found evidence that calling in sick from the job became less frequent when workers' compensation for sick leave were reduced (   ). Moral hazard has also been noticed by several other analysts,  like Boyer, M. and Dionne, G. (1987). The economics of road safety. Transportation Research-B, 21B, 413-431; Worrall, J.D. (198).
Others reported that increases in workers’ compensation payments for injuries may increase the rate of workplace accidents. (Worrall, J.D. (1983). Safety and the workforce: Incentives and disincentives in workers’ compensation. ILR Press, New York State School of Industrial and Labor Relations, Cornell University).
Phrased in simple terms: to offer people protection against the consequences of risky behaviour encourages risky behaviour; to offer people better protection against the consequences of risky behaviour encourages riskier behaviour still.
Automobile and other insurance sells peace of mind, which is nice, but it is also a problem for that very reason. This is, as mentioned earlier, why automobile insurance at one time was forbidden by law in some countries.
This is not to say that we should not have automobile insurance, but obviously the consequences should be seriously considered and insurance practices should take them into account.
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Self-reported driving behavior may only predict self-reported accidents and not those that are actually known to have taken place.
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Now that was a tricky question. All my research into this indicates that self-reports of driver behaviour and accidents usually are very unreliable and biased in various ways. So, what can we actually use them for? Well, such data can tell us things about how the human mind works, and possibly also something about why drivers behave as they do in traffic.
For example, studies on forgetting of crashes indicate how poor our memories are. This is similar to memory studies in the lab, but in a real setting, and can therefore tell us things about how we remember important/aversive happenings in real life.
.But we could also possibly understand why drivers do not correct their own dangerous behaviour in traffic. The responses given in questionnaires, if compared to actual behaviour, may tell us something important about this. For example, if drivers selectively remember certain aspects of their driving, this may be what is important to them. This could be a way to educate drivers, showing them the discrepancy between their self-image and reality.
Now, this is all very much from the top of my head right now, but I must say that if we are to learn from self-reported driving behaviour and crashes, I think we need a new take on how to use this kind of data.
As for your specific question about predicting crashes from self-reported driving behaviour, I think there is very little we can learn there, apart from the need to be very cautious with this kind of data.
As for references on which I base these statements, they can be found on my Rg page.
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I'm trying to calculate the exposure to risk of horse riders in the UK when riding on road to collisions i.e. collisions per rider per km.
Does anybody have any values of the average amount of riding in the UK; similiar to what is found for pedestrians and pedal cyclists in the national travel survey?
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Thanks Edmund 
Thats a great help!
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In road safety, treatment of crash locations (black spots) is typically addressed with a single treatment for the most common crash (accident) type. For instance, if there are multiple cross intersection crashes, you install traffic signals (an oversimplification). There is a crash reduction factor (CRF) for this (or CMF in some countries).
My question relates to treating a given crash location with multiple treatments to increase effectiveness (???). For the example above, it could be installation of traffic signals, high-level street lighting and reducing the speed limit. CRFs are available for each treatment type in isolation. How does one confidently estimate the overall crash reduction factor for such multiple treatment? Is there any robust research on such method? 
We have published on this subject previously, but the method is very simple and not adequate for many situations.
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Hi Chris, very good question as usually :-) There is a discussion going on in this field, starting from Elvik (2009) - https://www.researchgate.net/publication/26305766_An_exploratory_analysis_of_models_for_estimating_the_combined_effects_of_road_safety_measures_Accid_Anal_Prev
I am sure you know about the multiplicative method - and its limitations. It is still under research - a NCHRP project, finishing soon, will hopefully give some answers (http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=3421).
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Hi,
I am conducting random parameter multi-vehicle crashes modelling and found my data has 96% of zero crashes. What are the best method in solving excess zeros data and on the same time to capture unobserved heterogeneity?
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As you are concerned with the excess zeros, So its better to try Zero Inflated Negative Binomial Regression. You can use random effects zero inflated Negative binomial model. Please visit the link below> Hopefully you will get an idea
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Hi, Who has experience calculate elasticity and partial effect manually for random parameter negative binomial? I have tried many times but didn't get the same value with software. I am using Nlogit 5 software to run my model.
Best Regards,
Rusdi
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You can calculate the elasticities and partial effects using the mean values for the variables, or you can calculate them for all observations and take the mean values. This will give you two different estimates. With random parameters, you will need to use the ": Parameters" option in the model code and use each observation to get the same value as the software.
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We are studying the feasibility of using rumble strips to reduce the ROR accidents in Chile. We are looking for research and standards in Europe, South America and Oceania about this device.
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Dear Bjorn
Thank you very much for your extensive contribution. In my laboratory we are preparing a driving simulator with which we expected to study rumble strips. Your work is very helpful for our research!
Best regards
Tomas
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I am going to develop and validate a questionnaire to study pedestrian unsafe crossing behavior based on extended TPB. After conducting qualitative phase for eliciting salient beliefs I will use the results to develop a questionnaire. In addition to standard constructs of TPB, one of the extended predictive variables would be past behavior. I would also be measured unsafe crossing behavior as an independent variable using a self-report questionnaire. Could anyone please help me how to formulate questions to measure past behavior as a predictive variable and behavior as an independent variable?  
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Dear Kamarudin & Dear Syed Muhammad,
Thanking you for your recommendations. According to the rules of TPB questionnaire construction, we have to define the behavior of interest in terms of its target, action, context, and time elements. Defining the behavior in terms of time element is problematic. Because when you set the time e.g. for the past two weeks, the behavior of interest would be indeed, the reflection of past behavior, and when you want to measure the past behavior you will come up with the same question you set for the behavior.
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Driver physiological measurement (hear rate, eye blinking, sweating....)based workload measurement methods for evaluating road geometry
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If you are not succesfull, let me know and I could maybe copy some selection for you. Good luck!
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what steps must I do for implementation of haddon method?  
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In line with Mr Zulhaidi Mohd Jawi, I attach here a simple application of Haddon Planning Matrix and hopefully it would assists you to have clear understanding.
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I am working on a report to investigate the possibility of developing models of remaining life prediction from the measurement of road roughness 
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Marwan, do you mean curvature or surface quality? in the first case you probably can use GIS information to calculate different parameters of road geometry. For the 2nd question you should either ask for drivers' experience or make field measurements. But given your question, you should also develop a model about the link between road geometry and the probability of an accident.
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Perceived danger acts as a major barrier to the uptake of cycling as a sustainable mode of transport. Therefore, a greater understanding of how these perceptions arise and how they are overcome is necessary.
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Hi all,
I have published a new paper on this area, which uses mental mapping and a Generalised Linear Mixed Model to unpack perceived cycling risk: http://www.sciencedirect.com/science/article/pii/S0001457515301688
Richard
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After doing preliminary research scan (lots and lots of semi-relevant research), I am still looking for research on motorway conditions where pavement quality generally good, and the variation in roughness (IRI), regulation, micro- and macrotexture are fairly small. Is there still a detectable effect on safety outcomes? If so, for which crash types? Seminal and leading research leads will be appreciated. 
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You might find help, at least on the methodology, in this study of accidents on all types of roadways (not just highways), their geometry and detailed surface conditions (ch 9, enclosed).
If you want more details, you have to look at the final table in the detailed paper, enclosed also. The last variables in the list (Groups 13 and 14) are all surface quality variables. But the source of the data, the French technical road services, forced us to hide the detailed results for eight variables (A...H) in that section. They were afraid of lawsuits, as were occurring in Germany at the time, based on the idea that better surfaces increase speed and perhaps accident risk or severity.
Hoping this helps. Marc Gaudry
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I think it's possible to apply internet of things to ensure safe driving. For example, you can watch the video of Samsung Safety Truck. Now I would like to do a research something like that but I couldn't find any paper on that project. In that case, how can I cite them in my work?
It would be also helpful if anyone can suggest some relevant papers. 
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Hello everyone,
I am now trying to simulate crashes in VISSIM 7.0. I know VISSIM could not generate crashes during the simulation. So I am looking for some alternative measures, such as add one public transportation stop, signals or parking lot at a given crash location. Does anyone has the similar experiences with VISSIM and I am looking forward for your suggestions.
Thank you very much.
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Hi Peibo,
Thats right, what is the objective you want to achieve ?
Driving behaviour, can cause delay and increase vehicle travel time, you can also customize vehicles desired speed, behaviour and lane change, that will cause some traffic problems.
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I already have known the driver education of Sweden, but I need it more detailed.
For example:
Once I read that there is 4 hours obligatory skid training, and in other report there was 6 hours mandatory risk education.
Which is right?
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Thank You very much Susanne!
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i wanna do research about mesoscopic traffic flow parameters which affect crash severity in urban highway. i know that mesoscopic parameters are combination of macroscopic & microscopic parameters. but what kinds of variable should i consider for making a crash severity models
thanks for your time and consideration
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Crash Severity on a urban highway, as on other roads, mainly depends on the kinetic energy. The kinetic energy by the speed. The speed by traffic flow, density, lane width, tortuosity of the route etc.
I would check the following parameters in function of the crash  severity:
number and width of lanes, traffic flows per lane (in passenger car equivalents per hour), composition of traffic flow, speed (85th percentile or speed diagrams for the entire path), speed differences among different types of vehicles (such as cars, vans, trucks etc).
The interdependence of these parameters and the crash severity should give you some good results.
Good work and good luck
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There are many contradicting views on the impact of pre license training on skill development and safety of novice drivers/motorcyclists. Do they agree on any particular skills improvement or anything?
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Unfortunately, there is relatively little research on motorcyclists, as compared to most other road users. I would therefore say that the views you have encountered are just views and not much more. The empirical foundation for them is slim indeed. Looking through my own collection of papers on traffic safety, I find the following ones. I am not an expert on this problem, but I hope you can find some guidance here.
Cheng, A. S., Ng, T. C., & Lee, H. C. (2011). A comparison of the hazard perception ability of accident-involved and accident-free motorcycle riders. Accident Analysis and Prevention, 43, 1464-1471.
Chesham, D. J., Rutter, D. R., & Quine, L. (1991). Mapping the social psychological determinants of safe and unsafe motorcycle riding. In G. B. Grayson & J. F. Lester, Behavioural Research In Road Safety I, pp. 148-155. Crowthorne: Transport and Road Research Laboratory.
Chesham, D. J., Rutter, D. R., & Quine, L. (1992). From theory to practice in the design of safety training: Promoting habitual accident avoidance by novice motorcyclists. In G. Grayson (Ed.) Behavioural Research In Road Safety II, pp. 108-116 Crowthorne: Transport Research Laboratory.
Jonah, B. A., Dawson, N. E., & Bragg, B. W. (1981). Predicting accident involvement with the Motorcycle Operator Skill Test. Accident Analysis and Prevention, 13, 307-318.
Langley, J., Mullin, B., Jackson, R., & Norton, R. (2000). Motorcycle engine size and risk of moderate to fatal injury, from a motorcycle crash. Accident Analysis and Prevention, 32, 659-663.
McDavid, J. C., Lohrmann, B. A., & Lohrmann, G. (1989). Does motorcycle training reduce accidents? Evidence from a longitudinal quasi-experimental study. Journal of Safety Research, 20, 61-72.
Mortimer, R. G. (1988). A further evaluation of the motorcycle rider course. Journal of Safety Research, 19, 187-196.
Preusser, D. F., Williams, A. F., & Ulmer, R. G. (1995). Analysis of fatal motorcycle crashes: Crash typing. Accident Analysis and Prevention, 27, 845-851.
Radin Umar, R. S. (2006). Motorcycle safety programs in Malaysia: how effective are they? International Journal of Injury Control and Safety Promotion, 13, 71-79.
Soderstrom, C. A., Dischinger, P. C., Ho, S. M., & Soderstrom, M. T. (1993). Alcohol use, driving records, and crash culpability among injured motorcycle drivers. Accident Analysis and Prevention, 25, 711-716.
Supramaniam, V., van Belle, G., & Sung, J. F. (1984). Fatal motorcycle accidents and helmet laws in peninsular Malaysia. Accident Analysis and Prevention, 16, 157-162.
Harrison, W. A. (1997). An exploratory investigation of the crash involvement of disqualified drivers and motorcyclists. Journal of Safety Research, 28, 213-219.
Horswill, M. S., & Helman, S. (2003). A behavioral comparison between motorcyclists and a matched group of non-motorcycling car drivers: factors influencing accident risk. Accident Analysis and Prevention, 35, 589-597.
Jonah, B. A., Dawson, N. E., & Bragg, B. W. (1982). Are formally trained motorcyclists safer? Accident Analysis and Prevention, 14, 247-255.
Leaman, A., & Fitch, M. (1987). Impulsiveness and venturesomeness in young motorcyclists. Personality and Individual Differences, 8, 945-946.
Mannering, F. L., & Grodsky, L. L. (1995). Statistical analysis of motorcyclists’ perceived accident risk. Accident Analysis and Prevention, 27, 21-31.
Maycock, G. (1991). The accident liability of motorcyclists and car drivers. In G. B. Grayson & J. F. Lester, Behavioural Research In Road Safety, pp. 68-85. Crowthorne: Transport and Road Research Laboratory.
Chesham, D. J., Rutter, D. R., & Quine, L. (1992). From theory to practice in the design of safety training: Promoting habitual accident avoidance by novice motorcyclists. In G. Grayson (Ed.) Behavioural Research In Road Safety II, pp. 108-116. Crowthorne: Transport Research Laboratory.
Elliott, M. A., Sexton, B., & Keating, S. (2003). Motorcyclists' behaviour and accidents. In Behavioural Research in Road Safety XIII, pp. 139-152. London: Department for Transport.
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I am working on pavement performance so need to determined PSI.
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I support the good answer stated by dear Rawand. To complete the mentioned explanation, it may be noted that the primary factor which is used in the existing literature to determine the PSI may be considered to be longitudinal roughness. Thus, some researchers have not used the other factors, e.g. cracking, patching, etc., in their correlations. Therefore, PSI may be determined solely by the use of pavement roughness, especially for the rural pavements, with a high degree of accuracy.
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In order to fill wheel rutting with micro-surfacing mixture, I need some references or useful papers to study.
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Hello Raheb -
The University of Texas at Austin - Center for Transportation Research hosts the on line library for the Texas Department of Transportation which is at the following link:
If you will type in the word 'microsurfacing' in the key word search field you will find several research reports and other resources that address use of microsurfacing in Texas.
Hope this helps.
Dr. Mike Murphy
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I would like to know data from foreign countries.
For example in Hungary it is about 56-57%.
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Thank You for your answers!
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This formula is used to specify whether their is a need to provide pedestrian crossing facility or not. Its value is taken as 10 E+8 for undivided road and 2x10E+8 for divided road.
Why is it doubled in the case of divided road?
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Dear Rajat,
The pedestrians would be conflict (with the vehicle traffic) two times for the divided road. But in case of undivided road it's half of the divided case. 
If you explain more about the problem, I can answer more.
I hope this would be helpful.
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What are the best method to compare frequency of two crash locations?
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If you have no denominator data for the sites (eg no of vehicles passing/unit time, population density of area) you could use a comparison of Poisson variables ,using  crash counts in successive time periods as basic data.
If you have denominator data you could use comparison of proportions with exact binomial statistics or normal approximation.
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I am referring the code IS : 15592 : 2005 and it is claimed that it is identical with ISO 8608 : 1995 ‘Mechanical vibration — Road surface profiles — Reporting of measured data’.
The road profiles are classified A-H according the degree of roughness which is the PSD G(n) m^3/cycle at reference frequency no = 1/(2*pi) cycle/m or in circular units G(w) m^3/rad and reference frequency wo = 1 rad/m.
The relation between the two PSDs is: G(n) = 2*pi*G(w) = 6.28*G(w).
Now referring to the attached sheet it, the degree of roughness are expressed in both the units which is not confirming to the above relation, the relation seems to be G(n) = 16*G(w). This confusion is also seen in many standard journal papers.
Which one is correct Table C.2 a) or b)?
Can anyone provide clarification regarding road profile classification by ISO 8608?. Available from: https://www.researchgate.net/post/Can_anyone_provide_clarification_regarding_road_profile_classification_by_ISO_8608 [accessed Mar 31, 2015].
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Could you please visit https://scholar.google.com.my/ and key-in your keywords, InsyaAllah you will get some information about your question.
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For national (or regional) road safety evaluations and comparison we have been using two safety performance indicators (SPIs):
- direct (crashes, fatalities, injuries...)
- indirect (speed, speeding, seat belt use, daytime running lights use, cell phone use...)
Now I am trying to find some correlations between them. And I ask, for example: Should percent of speeding correlate with crash counts? or with fatalities? or injuries?
All is done on the level of country (or regions) - so direct SPIs are from national/regional statistics. Indirect SPIs are from surveys, typically 7 locations per region, once per year.
And lots of other questions, for example: when surveys are done in weekdays, spring/autumn, dry weather, should crashes to correlation also come only from the same conditions? (or possibly even only in the days/hours of survey?)
I will welcome any ideas on how to do these analyses, references, etc. Thank you in advance.
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When discussing correlations you have to keep in mind that correlations do not necessarily imply causal relations. Often, they are a consequence of a common influence by an ignored third factor such as properties of the infrastructure (many or few freeways), regional structure (predominantly urban or countryside), cultural properties,  (liberal or strict) legislation, (sloppy or stringent) control/enforcement. For example, in countries with liberal speed regulations (e.g., 75 or even 85 mph allowed on some roads) and sloppy enforcement (hardly any speed limit monitoring), few speed tickets are issued, i.e., the statistical data show little speeding. Nevertheless, in an objective sense, there may be many drivers driving too fast for the given situation resulting in comparatively many accidents.  This results in a paradoxical correlation with an unexpected sign between speeding and accidents.  This is a variant of the classical Simpson's paradox: The more firefighters are sent to the scene, the more damage the fire will  cause.
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What is the suitable ITS plan for traffic problems in developing countries with dense traffic jams and absence of traffic control plans. In such cases, is the environmental dimension considered in planning a new ITS system for developing countries societies? Or, just to focus on the operational performance of the street network.
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Information and education - the most important factors. It is very important to get society (and institutions will be involved in the process) acceptance before implementation.
You can start with ITS architecture e.g. eframe (http://www.frame-online.net/)
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I am referring the code IS : 15592 : 2005 and it is claimed that it is identical with ISO 8608 : 1995 ‘Mechanical vibration — Road surface profiles — Reporting of measured data’.
The road profiles are classified A-H according the degree of roughness which is the PSD G(n) m^3/cycle at reference frequency no = 1/(2*pi) cycle/m or in circular units G(w) m^3/rad and reference frequency wo = 1 rad/m.
The relation between the two PSDs is: G(n) = 2*pi*G(w) = 6.28*G(w).
Now referring to the attached sheet it, the degree of roughness are expressed in both the units which is not confirming to the above relation, the relation seems to be G(n) = 16*G(w). This confusion is also seen in many standard journal papers.
Which one is correct Table C.2 a) or b)?
Is anyone have the original ISO 8608 code?
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I will explain in detail soon
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I'm trying to relate speed selection behaviour with crash occurrence. There have many research on that in literature but I still don't found any suitable method on that.
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Dear Eng. Rusli
There is a lot of literature. I myself is preparing an article regarding design consistency and crash prediction model. Speed in one of the most important factor. You may try this reference. It is comprehensive.
Awatta, M. Highway Design Consistency and Safety: Individual and Overall Evaluation Criteria. Ottawa, Canada: Carleton University; 2003. 
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The most usual way to do this is the ratio  (crashes) / (billion vehicle km travelled). But what if we don't have AADT data? Is it right to calculate the ratio (crashes) / (road length) for 2km road segments? The 2km is an example of course..  Thank you in advance!
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Dear Ioannis, you ask very important question. There are various perspectives and indicators. As you mention, crashes are the typical indicator. But are they the best one? It depends on crash frequency, time frame adopted, extent of underreporting... - how many crashes do you typically have in your conditions? Is the frequency sufficient for the analysis you need? If not, other indicators may be used, based on more frequent events, such as for example traffic conflicts.
Nevertheless AADT is usually the most important condition, this is why it is used as exposure indicator - and risk is basically count of events related to exposure. Some good reading - http://www.swov.nl/rapport/R-2002-12.pdf
Regarding section length - there are discussions about it. If you need risk related to some conditions, then these conditions should dictate how are section formed (segmentation). See for example here - http://docs.trb.org/prp/13-4372.pdf
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A road passes through/towards populated areas. How can we determine the importance of this road? One way is of course by measuring the road safety it offers to the local society. Another way to do that is by determining the importance of these areas (number of citizens, existence of airport etc). Can you suggest me a scientific way to do that? Thank you!
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some of the items:
1. no of users
2. benefit gain
3. time saving in travelling
4. economic benefit gained form the project
etc
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By skid car training I mean a post license training, especially for young/ novice drivers using a specially prepared car without a fixed rear axle, but with a construction using 360 degree rotatable wheels.
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Hi Walter
I'm not sure if you have seen the attached - but just in case.
Best wishes
Lisa
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I have been developing various regression models for road crash frequency. I use generalized linear models (SPSS GENLIN or SAS GENMOD procedures), negative binomial (NB) distribution, log link function. For example: annual crash frequency on road segment = a x (traffic volume)^b x (curvature change rate)^c etc. Now I am trying to assess individual impact of variables, let's say traffic volume or curvature change rate. From literature I am not aware of any standard procedure for that. I have seen various charts (predicted crash frequency on Y-axis, traffic volume on X-axis) or tables with "impact coefficients" (example: standard traffic volume equals impact 1.0, increased traffic volume = impact 1.5, etc.). I also saw calculations of elasticity or marginal effects, but usually only for Poisson regression and I am not sure whether the same applies for NB. I would like to find some specific paper dealing with this issue AND dataset used so that I would do calculations myself to obtain the same results to make sure I know how to do it. Could somebody help me with this, please? Thank you.
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Please use step wise multiple regression models and multivariate analysis to know the impact of every variables.
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I am aware that a large sample will be needed, but I am not aware of a formula to compute the sample size.
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A good paper that discuses this issue is "How Many Accidents Are Needed To Show A Difference?" by Ezra Hauer.  Here is a link to the article: http://www.sciencedirect.com/science/article/pii/S0001457508000535
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I am interested in this area especially in the field of road infrastructure, both on highways and urban roads.
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Hi,
concerning ITS for motorcycles, the PISa project (www.pisa-project.eu) proposed a prioritisation of safety functionalities to be integrated on powered two wheelers, based on estimated influence in real-world motorcycle crashes.
Attached is a link to related Executive Summary.
This activity was briefly presented at some conferences (see attached), but with poor details. And as far as I know there is not a journal paper on that.
I hope it is of help.
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I have to compare the crash characteristics two roads at two different geographical conditions, A and B. A have their own segments A1,A2,A3 and A4. B also have their own segments B1,B2,B3,B4 and B5. Every segments have their own crashes, length and average annual daily traffic(AADT). Should I compare the total of crashes (by consider total length and AADT) for both roads or doing separately by segments and after that compare the average?
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I recommend the following website; it is helpful.
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What are plausible explanations for these results which seem to contradict most other traffic safety studies (that have consistently found higher risks for men and for older cyclists).
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@Xochitl
Experience can certainly be a factor, but one which is hard to disentangle from a general decrease in risk taking behaviour with age (perhaps based on near misses or real accidents)
@Vincenzo
Distraction is certainly one of the top causes cited by cyclists involved in an accident in Belgium. However is it unclear to me why women would be more distracted than men (in Belgium and the other way around in other countries)
@Yves 
The population was limited to those of working age and mainly focussed on commuting so probably not due to differences in time activity pattern.
However on the gender issues I think you may have a point. Some of the men in the study reported really long commuting distances along e.g. canals where accident risk (per km cycled) is probably very low. On the other hand women seem to take trips more often in the rush hour (e.g. AB modelling by Beckx et al) and in town centres with more intersections and therefore higher risk (while their risk aversion while driving/cycling) may still be higher than that of men)
@Henk
Thank you for the Dutch graph. The reversal of male/female risk ratio with age is really interesting. The SHAPES sample was limited to those of working age (<65) and the number of observations in the +50y was indeed very low. On the other hand we are very confident in our assessment of the distance cycled which we observed frequently during a whole year.
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At present, the UK is out of step with Europe as one of only five EU countries (along with Cyprus, Malta, Romania and Ireland) that does not operate some form of strict liability regime for vulnerable road users. Strict liability is already established in other areas of UK law. As a consequence, our current system expects those injured or the families of those killed to go through an often harsh and protracted process to gain much needed treatment, care or compensation. On the Continent, strict liability regimes are seen as an integral factor of cycle safety and Scotland has the power to introduce this principle into civil law to demonstrate its credentials as a civilised, cycle-friendly nation. It is no coincidence that countries operating a Strict liability regime in Civil Law are often those with safer roads for vulnerable road users.
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We have a trend of cyclist fatalities per billion kilometres cycled in the Netherlands. The fatality risk has been gradually decreasing. Strict liability was introduced in the Netherlands in 1990. There is a debate about the effect: http://bicycledutch.wordpress.com/2013/02/21/strict-liability-in-the-netherlands/
The data do not show an additional decrease around 1990 after the law was introduced. Nevertheless, I agree with this policy. Cycling has many advantages and is something governments want to encourage. And to quote the above referred website: “Strict liability tries to be a fair answer to the inequity in the consequences of a crash”.
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I am interested in examining the traffic safety situation of some cities/ towns in my country. Does anyone have expertise in this field by way of research?Is there any model I should know about? What should I consider in terms of variables?
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Dear Enoch,
I quite agree with Satish Chandra.
The study of traffic safety, urban (or not) starts from the data. These can be at different levels of depth depending on the results you want to achieve: general strategy, action planning, design of the countermeasures. From the statistical data down to single police reports.
You try to give a quick read to ANALYSIS OF ROAD SAFETY: THREE LEVELS OF INVESTIGATION that I have made available now.
Then you let know me.
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Anyone has a theoretical model in mind? 
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Oscar,
Rob Alexander, at University of York, is working on a related task for autonomous vehicles. His concern is not so much the complexity at any given time, but how to measure whether you have tested the vehicle in a sufficiently wide range of circumstances.
To answer your question more directly, you've got a chicken-and-egg evaluation problem when the question is phrased as you have phrased it. No matter what measure of complexity you come up with, how do check whether it is valid?
Let's say you find that "more complex" situations make no difference on driver performance. What would you have actually worked out? Probably just that your measure of "more complex" isn't very useful.
Let's say you find out that "more complex" situations make drivers perform worse. Cue a total lack of surprise in everyone who reads the results. What you'll have actually done is indirectly validate the complexity measure rather than learned something about drivers. I say indirectly, because a correlation between a multi-element measure and a dependent variable doesn't tell you which elements are causing the variation, unless you designed the experiment that way in the first place. 
Arguably, the complexity of a road situation should be measured by measuring its impact on drivers. A complex situation is one where drivers perform consistently worse on the driving task, with non-situation variables controlled. That then allows you to validly determine what increases or decreases the complexity.
In that case it isn't a theoretical model at all. It's an empirical model in search of an explanatory theory.
I could have misunderstood your question though. Are you looking for a measure of complexity which is already shown to validly relate to driver behaviour, that you can take away to use for another purpose?
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Man commits movement at different targets (employment, education ...). In this case, he can use a private car, and maybe in other ways - by public transport, on foot, bicycle .... Our research shows that the probability of being involved in a road traffic accident using public transport is much lower than when using personal vehicles. Because with this it would be interesting to know the results of studies on the effect of the quality of passenger traffic (speed, density of the route network, etc.) public transport on the distribution of modes of transportation, and as a consequence, on road safety.
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