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Traffic Safety - Science topic
Explore the latest questions and answers in Traffic Safety, and find Traffic Safety experts.
Questions related to Traffic Safety
Are you aware of a study that estimated the number of people who are permanently (psychologically) affected by a single road fatality?
For example, on average # of family members, # of close friends, # of eyewitnesses, # of rescue personnel... are permanently affected by a single road fatality.
I have seen several people talking about such numbers, but they never provide a reference to the original study.
Thanks.
Evidence is emerging that long COVID can cause cognitive and visual deficits. Given the large numbers of people potentially affected, I am concerned about the effect on traffic safety, particularly in the current context of very high rates of fatalities and serious injuries. I have not seen any research directly on this topic. Would appreciate any pointers to ongoing or recent studies. Lila Ralston, Program Consultant, 55+ Driver Safety Program, Georgia Department of Public Health.
Surrogate Safety Measures (SSM) are used to measure traffic safety. Some video-based software can generate these values from real vehicle traffic videos. So, is there any device that can be mounted on a vehicle, is portable and can measure all/some of the SSM metrics?
Hello, I have a questionnaire that consists of five sections. The first section (related to drivers' knowledge) has 10 items with no Likert scale and the participants have to choose from either two or three or more specific options. The second section (related to drivers' habits) has 9 items with the first five items having a six-point Likert scale while in the remaining items the respondents have to choose one question from four specific options. The third section (related to drivers' behavioral intentions) has 10 items with each following a six-point Likert scale. The fourth section (related to drivers' psychological conditions) has 9 items with no Likert scale and the participants have to choose from three, or four or more specific options. Finally, the last section consists of questions regarding drivers' profiles (age, gender, education, driving experience, profession, frequency of driving through tunnels, etc.)
Now my question is, what kind of statistical tests or analysis can I perform here to investigate the relationship between the variables in the drivers' profile and other sections/items. For instance, how I can analyze which group of drivers (in terms of age, gender, experience, etc.) are more knowledgable (section 1) or adopt appropriate habits (section 2).
I am also open to all kinds of suggestions and collaborations on this research.
P.S: I am attaching my questionnaire as a file. Hope it will help to understand my question and questionnaire better.
To study the impact of public transport on traffic safety on urban road networks and traffic at bus stops
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?
the traffic light sometimes is easier to cause the traffic jam problem, if the designer don't make to many change to the both side of the road,such as the house and block building, what other aspect of things can be done to mitigate the traffic jam problem.
There is a famous Venn diagram (see attachment) that shows 93% of crashes are due to drivers: 57% solely due to drivers, 27% due to their interactions with roadway, 6% due to their interactions with vehicle, and 3% due to their interactions with both. But these figures are from very old studies:
- Rumar, K. The Role of Perceptual and Cognitive Filters in Observed Behavior, Human Behavior in Traffic Safety, eds. L. Evans and R. Schwing, Plenum Press, 1985.
Rumar (1985) compared statistics from a 1975 UK and a 1980 US study. The US study was based on an Indiana study as follows:
- Treat, J.R. A study of precrash factors involved in traffic accidents, Highway Safety Research Institute (HSRI). USA. The HSRI Research Review 10, 6, 11, 1. 1980.
So, are there recent studies on roadway crash causes?
Especially considering the significant changes in the contributing factors leading to roadway crashes.
Venn diagram source: Interactive Highway Safety Design Model: Accident Predictive Module (1994) https://www.fhwa.dot.gov/publications/publicroads/95winter/p95wi14.cfm

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!
Ethical issue is one of obstacle for the development of driver-less vehicle. For example, when a driverless car travels on a one-way road, unfortunately an ignorant pedestrian rush into the road. In such scenario, it is very difficult for the vehicle to make a decision: to brake and hit the pedestrian or veer and to run off the road, leaving passengers injured. Obviously, different action will lead to different consequences. One is the serious injury to pedestrian; another is the harm to the occupants inside the vehicle. Whatever, there will be a victim to be injured and the driverless car will be accused. Certainly, we should keep people out of the highways. Even so, due to the large number of vulnerable road users who travel around all the time, they will be the main objects for driver-less cars to avoid collision. Therefore, the relevant ethical issues should be considered and addressed first before driverless cars get offer to enter the road. Let’s suppose more possible and dangerous scenarios and discuss them.
i am carrying out a study on drivers and pedestrians compliance to traffic signs and signals in a metropolis.
how will i go about the data analysis
i used questionnaire to obtain data on compliance
i also obtained data on compliance from traffic agency in charge of traffic safety
and also conducted observational study
how do i combine these data sources to test my hypothesis
I have 15-minutes traffic volume count data at different locations along a highway stretch. With this data, I want to calculate ADT and AADT.
please share material regarding the same. highly obliged
Including (car following and lane changing data and more driving tasks)
it will be great if the data tagged with current driving task.
The existing route direction of vehicles ( please check figure in below) in a city has been drawn for a research. Are the number of conflicts at each intersection drawn correctly? Would anyone kindly evaluate the drawing and give any suggestion?
N.B: Please name the intersection as CMM, PMM, KGM, TM, IM

How can we decrease the effect of cameras on driver behavior during a naturalistic driving study?
AASHTO (2001) talks about a value of 4.5 m/sec2 as it was observed that most of the drivers decelerate at a rate greater than 4.5 m/sec2 when decelerating for an unexpected condition.This value may or may not be applicable for Indian Traffic condition which is highly heterogeneous in nature. This situation is characterized by different vehicle categories with diverse static and dynamic characteristics, changing composition, lack of lane discipline. Does it mean that I need to use different DR values for different category of vehicles under different traffic facility? I could not get hold of accident reconstruction specialist who could have helped me in this regard. Kindly advise.
PhD Student Positions Available (Summer 2019 / Fall 2019):
There will be 1-2 PhD Student Positions available in the Department of Modeling, Simulation & Visualization Engineering (MSVE) at Old Dominion University. Students are expected to work on Transportation Research projects, with a focus on Data Analytics, Artificial Intelligence (AI)/Machine Learning, Virtual/Augmented Reality (VA/AR), Transportation System Modeling & Simulation, and/or Transportation Safety.
If you are interested in the opportunity, please email me (E-mail: hyang@odu.edu) your detailed CV and other supporting information (e.g., sample publications, GRE test score, etc.).
Thank you very much!
I'm researching driver behaviour on the approach to signals and need more data on how drivers react and adjust their speed under the following conditions:
1) lead platoon with red signal - no queue at stopline
2) lead platoon with green signal - queue visible and discharging
3) lead platoon with green signal, anticipating onset of red before stop line is reached
I am interested in the variability in reaction time, point of reaction, deceleration rates over 3 stages- @foot off, @brake applied, and @coasting to final stop
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
I want to calculate the lateral shifting / lane changing behaviour of vehicle in a traffic stream. I want to know about some methods by which practically this distance can be calculated on road?
Usually Time headway is calculated as the time difference between two vehicles (front-front bumper of rear-rear bumpers) on the same position (same lane). in non lane based traffic it is the same but the position is a line on a road stretch (the same direction). what are the motivations behind using the whole road stretch ? In my case I have a road of 3 lanes (same direction) and I group two lanes to see the pattern of time headway. Meaning I calculate Time Headway based on a line along the two lanes. Does this make sense in traffic theory ? It does seem unconventional but since I have vehicle arrival with no respect to lane separators, it seems to me that the arrival of a vehicle in a position on the two grouped lanes is influenced by the preceeding vehicles no matter what it's position in the two grouped lanes.
P.S : Each lane in my scenario is of 3 to 3.25 meters width
Longitudinal seal repairs sometimes tend to cause severe instability in motorcycles under dry conditions in corners. Anecdotally it does not appear to be strongly correlated to road temperature, although on days with higher than normal surface temperatures it does soften causing the front to slide. I am looking for cases where this was identified as a cause and low-cost solutions to improve the traction of these seal repairs
My hypothesis is that surface ripples cause the following problems and could be an underlying cause of many run-off-road crashes in rural areas:
- in the braking zone the suspension could pack down due to a lack of compression damping causing longer braking distances and hence higher entry speed
- a rider's arms could stiffen up due to excessive forces feeding through the suspension delaying the turn-in point and also slowing the rate of turn-in,
- at the apex the bike is easily destabilised that may cause a mid turn adjustment causing a wider exit radius to be followed,
- on the exit it could cause instability under acceleration causing the rear to lose traction.
I am looking for evidence where surface ripples are correlated to loss of control crashes, and whether this affects all types of motorcycle crashes, or mostly those types that have relatively poor handling attributes (i.e. Cruiser vs. Sportbike designs)
I am working on highway design consistency so I wanted to know how to measure "Sight Distance" from the field mainly on horizontal curves in hilly terrains.
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.
Rear-end crashes involving multi-vehicle in expressways may be more serious in future. Now we are studying this crash type. For example, several vehicles follow each other with high speed and suddenly one of them goes wrong and serious crashes will occur. The characteristics, crash propagation, injury severity and influence factors should be focused. And the research methods could be mechanical modeling, accident reconstruction and computer simulation. Could you please introduce some relevant literature regarding multi-vehicle rear-end crashes? Thank you in advance!
I am modelling a 4 lane signalized roundabout in a country using right hand drive using a VISSIM microscopic traffic simulation model
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?
there are many works related to determining the accidents, while we want to estimate the time and location of possible accident. I would appreciate if anyone could introduce me any work in this regard.
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,
Forming a Checklist of relevant parameters on which the Model should be based on
I have developed a quantitative LOS criteria based on actual delay faced by pedestrians on Indian roads using cluster analysis. I have also conducted a user perception survey to understand the perceived pedestrian delay. I wish to develop an LOS criteria which is a combination of both quantitative delay and perceived delay. I can develop another LOS criteria solely based perceived delay, but I am not sure how to come up with a combined LOS criteria.
Generally said, I plan to validate a specific indicator X (derived from driving behaviour) which should be linked to traffic safety (accidents) on level of road sections. Validation should statistically prove this relationship. I can think of various ways (i.e. possible study designs), but I would appreciate your opinions and advices.
Option 1 - I can define, based on theory or experience, two conditions when X is safe and when is unsafe. This can be compared to accidents / no accidents.
Option 2 - I can collect X on many sections and link it with accident history.
Option 3 - I can choose the critical sections (based on accidents) and collect X there - thus I should obtain "unsafe" values of X.
Option 4 - naturalistic driving study = studying the drivers behaviour visually. When they behave "unsafely", values of X will be "unsafe".
These are only my theories - please feel free to comment! I will welcome discussion, references, etc. Thank you.
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?
How many times can I change signal timing plan at isolated intersections during the day?
I intend to use Lane Change Test (LCT) on a driving test track. Can someone please suggest me what is the ideal no. of lane change markers in one kilometer distance.
The glare is always harmful for drivers to watch and identify the road scene. I often feel uncomfortable when driving toward the Sun. So I think there may be some correlation between sunshine and the occurrence and severity of traffic accidents. How do you think of this issue? Could you give me any suggestions or recommend related references to explore this situation? Many thanks in advance!
For vehicle to pedestrian crashes, statistics results show that females are at higher risk in crashes. Female pedestrians have more fatalities than males without regard to age, height, weight or other characteristics. Why female pedestrians or cyclists are generally vulnerable than males? Is it truly a gender difference? Is it because males are naturally stronger than females? But we have no further research work. Could you recommend me some related papers or existing research findings? Any suggestions are very welcome!
I am fitting a SPF with Negative Binomial and the ADT was significant and negative. The data corresponds to rural mountainous with low traffic volume. Do you have any possible explanation for this? perhaps a similar experience? suggested references?
Thanks!
I am working on performance of rural roads so provide literature on PSR.
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
Pedestrian traffic island (also they named as pedestrian refuges) is one of the most effective and inexpensive ways to reduce the accident rate. Has anyone done research on the impact of the proportion of pedestrian crossings with islands on accident rates?
Also would be interesting the publications about the variations of the embodiment of traffic island, conditions and rules of their application and so on.
Aghabayk et. al (2015) explained that 'T' is the driver's reaction time in GHR model (page 86). While in the article 'Traffic Dynamics. Studies in Car Following', Chandler et. al. (1958) stated that on page 181:
"... the response of the trailing vehicle depends upon its driver's perception time, t1, his response time, t2, and the time of the response of the vehicle, t3"
Which one is it, only the driver reaction time or perception+reaction+vehicle response?
Both articles are linked.
Driving simulator is used to simulate the driving behavior like normal traveling on roads. It will stop the vehicle when crash happens. At that time, I always wonder why it couldn’t be designed as working continuously even a short period of time, and then we could know the behavior of drivers during collision. Due to the zero risk of this type of test, if necessary, maybe some accidents could be reconstructed through human involvement simulation in place of computer simulation.
For example, how the design of highway can influence patterns of eye movement and how it connects to traffic safety. Thanks!
I would like to know data from foreign countries.
For example in Hungary it is about 56-57%.
I am using Generalized Linear Models (GLM) to model influence of various explanatory variables on traffic crash frequency. After modelling, it is useful to interpret influence of these variables. I have read that elasticity or marginal effects are used to do it - but not many authors use them (both). Could someone please provide source data and results so that I could test my calculations on them? Thank you very much.
Who can give me some practical advice/examples on how to implement a Hidden Markov Model. I would like to use that in the traffic engineering context under various traffic flow conditions. E.g. on the approach to a queue, does driver maintain or slow down when he sights a queue or red light? From the literature I have one thing that seems to elude me is how to calculate or estimate the transition probability matrix.
Could you recommend any sources: How to measure influence of ITS services on traffic safety?
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.
Dear Researchers,
I need to calculate the probability of the vehicles having some kind of incidents/accidents based on the intersection characteristics (grade, signage, median, etc.). It will answer the question that, for example, how much the probability of head-on crashes would change if we add raised median to the intersection.
However, I was wondering if there is any method/model to be used that relates this probability to actual frequency. For instance, back to my previous example and given the probability of head-on crashes, we can determine 5 head-on crashes will occur on a given intersection.
Thank you!
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.
Hello, prompt, where you can see the data on accidents involving drivers with driving experience of 1 year in different countries?
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.
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.
Could you recommend any reports, books etc. about the influence of automatic incident detection or incident management on the traffic safety? especially road infrastructure...
I am interested in this area especially in the field of road infrastructure, both on highways and urban roads.
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?
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).

Im looking for evaluating traffic safety at un signalized intersections by micro simulation. while reviewing related literature, I came across a term 'post-encroachment time'. So, I kindly ask for some related information.
I am working on Bus schedule optimization. For which, I have read some research papers. Almost all of them have considered passenger waiting time, fleet size, frequency, etc as parameters for genetic Algorithm. I want some information on how these parameters are decided.
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?
I am interested in the programs themselves, as well as scientific methods of their development. Also of interest is the assessment of their effectiveness (how much money is spent/what is the effect obtained). I am also interested in the programs of public transport development.
ISO 39001 standard is related to the road traffic safety management systems.
In a chaotic traffic scenario, the only rule is to reach your destination as soon as possible by avoiding collisions with your nearest neighbours. It is a kind of directed random walk on the all possible available passages that change dynamically. Such a traffic situation is effective because it avoids collisions and everyone manages to reach his destination if the road doesn't become too crowded. So, it will be nice to see the simulations of the chaotic traffic. Have anyone ever seen such a traffic model?
In the recent weeks there were 3 aircraft 'incidents', one of which was fatal. So is driving preferable? Is road safety comparable to aviation safety?
Instead of other statistical or conventional approaches, what are the main reasons that are inductive for modelling?
Preparing a survey of young novice drivers, we are still looking for an appropriate wording of a question regarding the so-called „near misses“. If you know of an attempt to ask such events successfully in a survey, I’d be grateful for any tips regarding literature or formulation proposals.