Article

Operational Evaluation of Central Sharrows and Dooring Zone Treatment on Road User Behavior in Ottawa, Canada

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Abstract

The purpose of this study is to determine how new pavement markings (central sharrows and indication of “dooring zone”) influence cyclist and motorist interactions and positioning, especially with respect to the distance cyclists travel from the parking edge line. The markings are designed to discourage cyclists from riding in the dooring-zone area and to ride in the center of the travel lane to avoid serious safety hazards. A number of safety performance parameters were used to assess whether safer conditions existed after the new treatment was installed. Safe motorist behavior was defined as: (a) motor vehicle following a cyclist with or without visible oncoming traffic in the opposing lane, and (b) motor vehicle passing a cyclist at a safe lateral distance. Safe cyclist behavior was defined as: cyclist riding in the lane position indicated by the central sharrows and outside of the dooring-zone area. The findings indicate that the central sharrows and dooring-zone markings created more favorable conditions for cyclist safety and for motorist compliance. Cyclists rode further from the parking edge line and closer to the sharrows that were marked in the center of the travel lane, and motorists were shown to be less likely to pass and more likely to follow cyclists.

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... Automobilisten zouden eerst moeten kijken of er een fietser aankomt voor ze hun deur openen. Daarnaast kan het fietsen buiten de zogenoemde 'deurzone' helpen om opendeurongevallen te voorkomen (Pai, 2011;Schimek, 2018;Kassim, Ismail & McGuire, 2018). Het CROW in Nederland adviseert om op gebiedsontsluitingswegen met fietsstroken en langsparkeren een zogenoemde schrikstrook van minimaal 0,50 meter toe te passen tussen de fietsstrook en de parkeervakken (CROW, 2019). ...
... Het CROW in Nederland adviseert om op gebiedsontsluitingswegen met fietsstroken en langsparkeren een zogenoemde schrikstrook van minimaal 0,50 meter toe te passen tussen de fietsstrook en de parkeervakken (CROW, 2019). In Noord-Amerika wordt geadviseerd om een bufferzone van ongeveer 1,20 meter te creëren tussen parkeerplekken en een fietsstrook, om fietsers aan te moedigen buiten de deurzone te fietsen (Kassim, Ismail & McGuire, 2018;Schimek, 2018). Dit verhoogt tevens de zichtdriehoek van de fietser en zorgt ervoor dat fietsers meer opvallen vanuit het perspectief van een parkerend motorvoertuig (Pai, 2011). ...
Technical Report
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This research shows how parking lanes alongside distributor roads inside build up areas increases the risk on bicycle-motorvehicle crashes on road sections and intersections. The report is in Dutch, but an English summary is available. The research questions are: - Do parking facilities along distributor roads with bicycle tracks near distributor/access road intersections increase the risk of crashes between bicycles and motor vehicles? - What distance to distributor/access road intersections can be considered acceptable or safe for parking facilities along distributor roads? To answer the research question – and to gain more insight into what role parking facilities play in bicycle crashes in general – the following was undertaken: - A literature study of the risks cyclists run due to parking along distributor roads in general and parking near intersections in particular. - The development of a research database of intersection locations with the associated crash data, traffic data and infrastructural characteristics. This database is based on (open) geodata sources and GIS analyses to identify intersections, record intersection characteristics, and link the different data needed. - Analysis of BRON-registered (Database of Registered Crashes in the Netherlands) bicycle crashes involving parked vehicles or parking manoeuvres. - Development of Crash Prediction Models (CPMs) for three-legged distributor/access road intersections, with the risk factor being the distance of the parking facilities to the intersection.
... Automobilisten zouden eerst moeten kijken of er een fietser aankomt voor ze hun deur openen. Daarnaast kan het fietsen buiten de zogenoemde 'deurzone' helpen om opendeurongevallen te voorkomen (Pai, 2011;Schimek, 2018;Kassim, Ismail & McGuire, 2018). Het CROW in Nederland adviseert om op gebiedsontsluitingswegen met fietsstroken en langsparkeren een zogenoemde schrikstrook van minimaal 0,50 meter toe te passen tussen de fietsstrook en de parkeervakken (CROW, 2019). ...
... Het CROW in Nederland adviseert om op gebiedsontsluitingswegen met fietsstroken en langsparkeren een zogenoemde schrikstrook van minimaal 0,50 meter toe te passen tussen de fietsstrook en de parkeervakken (CROW, 2019). In Noord-Amerika wordt geadviseerd om een bufferzone van ongeveer 1,20 meter te creëren tussen parkeerplekken en een fietsstrook, om fietsers aan te moedigen buiten de deurzone te fietsen (Kassim, Ismail & McGuire, 2018;Schimek, 2018). Dit verhoogt tevens de zichtdriehoek van de fietser en zorgt ervoor dat fietsers meer opvallen vanuit het perspectief van een parkerend motorvoertuig (Pai, 2011). ...
Technical Report
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Dit onderzoek laat zien op welke wijze parkeervoorzieningen tot een verhoogd risico op fiets-motorvoertuigongevallen leiden op wegvakken en kruispunten binnen de bebouwde kom. De onderzoeksvragen luidden als volgt: - Verhogen parkeervoorzieningen langs GOW’s met fietspaden nabij GOW-ETW-kruispunten de kans op fiets-motorvoertuigongevallen? - Wat is een acceptabele of veilige afstand van parkeervoorzieningen langs GOW’s tot GOW-ETW-kruispunten? Voor de antwoorden op de onderzoeksvragen – en voor meer inzicht in de rol van parkeervoor­zieningen bij fietsongevallen in het algemeen – zijn de volgende activiteiten uitgevoerd: - Een literatuuronderzoek naar de risico’s van parkeren langs gebiedsontsluitingswegen voor fietsers in het algemeen en rond kruispunten in het bijzonder. - De ontwikkeling van een onderzoeksdatabase van kruispuntlocaties met bijbehorende ongevallengegevens, verkeersgegevens en infrastructurele kenmerken. Deze database is gebaseerd op (open) geodatabronnen en GIS-analyses voor het identificeren van kruispunten, het vastleggen van kruispuntkenmerken en koppelen van de verschillende benodigde gegevens. - Analyse van BRON (Bestand geRegistreerde Ongevallen in Nederland) op parkeerongevallen met fietsers: ongevallen waarbij geparkeerde voertuigen of parkeermanoeuvres een rol spelen. - De ontwikkeling van Crash Prediction Models (CPM’s) van 3-taks GOW-ETW-kruispunten met de afstand van parkeervoorzieningen tot het kruispunt als risicofactor.
... Sharrows and bike lanes, shown in Fig. 1b and a, are mid-block treatments designed to facilitate longitudinal travel along roadways for bicyclists and to encourage safe driving and bicycling behavior, such as increasing vehicle passing distances Brady et al., 2011;Apasnore et al., 2017), avoiding the "dooring" zone (Kassim et al., 2018), and reducing sidewalk or wrong way riding (Vasilev et al., 2017;Hunter et al., 2011;LaMondia and Duthie, 2012). Both sharrows and bike lanes are intended to inform drivers that bicyclists may be present in the travel lane. ...
... So far, the majority of research has been conducted from the bicyclists' perspective (Dozza et al., 2016), in-field behavioral studies (e.g., using video or surveys) (Kassim et al., 2018Apasnore et al., 2017;LaMondia and Duthie, 2012;Björklund and Åberg, 2005;Räsänen et al., 1999), or through statistical crash analysis (Reynolds et al., 2009;Räsänen and Summala, 1998;Abadi and Hurwitz, 2018;Hamann and Peek-Asa, 2013;Kondo et al., 2018). Although it is immensely important to continue research from that perspective, these studies often fail to uncover the underlying cause and psychological factors contributing to bicycle-automobile crashes. ...
Article
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Municipalities in the United States often encourage bicycling for the health, economic, and environmental benefits by implementing new and innovative bicycle infrastructure treatments. Unfortunately, many treatments are unfamiliar to or misunderstood by drivers, especially when lacking explicit rules (e.g., shared lanes). To date, research has largely investigated bicycle infrastructure from a bicyclist's perspective, but with little research from the driver's perspective. The objective of this research is to utilize a driving simulator to investigate driver behavior towards different bicycle infrastructure treatments when driver behavior is not provoked by an interaction with bicyclists. More specifically, this research intends to investigate the impact of bicycling frequency and treatment familiarity, as well as the combined effect of the two, on driver behavior at each treatment type. The treatments investigated are shared lane markings called "sharrows", standard bike lanes, bike boxes, and merge lanes. The results show that bicycling frequency significantly affects the proportion of drivers making eye glances at treatments. In addition, drivers more familiar with bike boxes stopped significantly further back from bike boxes, and drivers more familiar with merge lanes performed the merge maneuver significantly earlier. Furthermore, driver speed and lane positioning at bike lanes was significantly affected by the combination of bike lane familiarity and bicycling frequency, but not individually. This research is a first step towards understanding driver behavior and expectation of bicyclists; an essential understanding for infrastructure treatments that do not provide physical barriers between bicycles and automobiles, and instead rely on driver behavior for safety.
... For sharrows, Rubie et al. (2020) report five studies, four papers showing no increase in passing distances (Foletta et al., 2015;Hunter et al. 2011;Kassim et al., 2018;Love et al., 2012). One study (Lamondia & Duthie, 2012) observed larger passing distances on roads with sharrows and a share the road sign compared to roads without these. ...
Article
Marked on-road infrastructure for bicycle riders is a fast and cost-efficient way to expand cycling infrastructure and thus promote cycling as a means of transport. Infrastructure layout has been shown to influence cyclists' as well as car drivers' behavior towards cyclists in traffic observations, with on-street markings for cyclists in some circumstances reducing overtaking distances by car drivers. Simulator and online studies promise to provide a fast and easy way of rapid prototyping infrastructure layouts. But, despite of good face validity, how trustworthy are the results of both these research tools? In a case-study to inform planning authorities, two studies, one in a cycling simulator and an online survey, evaluated the effects of different on-street markings from bicycle riders' perspectives. Results showed that in mixed traffic stronger visual separation between parking cars and flowing traffic and a bicycle pictogram on the road induced greater lateral distance of bicycle riders from parking cars. This infrastructure layout was also rated as safe, comfortable, and comprehensible from bicycle riders' perspectives. From a methods' evaluation perspective, effects from the cycling simulator may be interpreted as behaviorally valid relatively between conditions only. Both methods offer a cost-effective approach to initially test infrastructure solutions by weeding out the less favorable ones in the early stages of the design.
Article
Problem: Cyclists riding next to parked vehicles are at risk of crashes with opening vehicle doors. A central position, out of this dooring zone, decreases such a risk but comes with other problems like potentially smaller passing distances kept by overtaking motorists or having to cross tram rails. Method: Factors influencing cyclists’ choice of position were investigated by showing a total of 3,444 German cyclists different traffic situations in two online surveys. In the first study (N = 1,850), parked cars, the position of a cyclist riding ahead in the presented images (towards the curb/center of the lane), and presence and kind of sharrows were varied. As the variation in results for the different sharrow types was negligible, in Study 2 (N = 1,594), only the most common type was used. Whether cyclists prefer to accept the risk of falling while crossing tram rails or the risk of being too close to the curb or parked cars was investigated, varying the presence of tram rails, which has not been previously researched. In both studies, respondents indicated which position on the road they would choose in the depicted situations and answered questions about subjective safety, a factor closely related to cyclists’ choice of position. Results: Cyclists chose positions farther towards the center of the road if there were parked cars and they chose an even more central position with tram rails. Respondents felt safer with sharrows on the road as well as in situations without parked cars and in situations without tram rails. Discussion and practical implications: The results indicate that, in addition to infrastructure characteristics, other cyclists’ behavior (descriptive norm) influences cyclists’ position on the road as well as their perceived safety. Implications for infrastructure design, especially regarding (the removal of) parked cars, are discussed.
Article
This study investigated the impact of two road treatments on cyclist behaviour using an bicycle simulator. The treatments were sharrows (presence or absence) at a roundabout and widening an on-road bike lane (width 1.2 m or 1.8 m) on a curved mid-block section of the road. Outcomes collected included count (e.g. number of lane excursions) and continuous responses (lane position upon entry into the roundabout, in metres from the curb). A convenience sample of 21 Perth-based participants was recruited between 1 July and 30 September 2021. The results found that the presence of sharrows was not significantly associated with the distance from the left curb when entering a single lane roundabout. However, females rode 0.44 m further from the left curb when entering the roundabout than males, which was significant (95 % CI = 0.02–0.85; p = 0.04). Riders, aged 26–40 years, also rode 0.61 m further from the left curb when entering the roundabout than riders aged 18–25 years, which was also significant (95 % CI = 0.18–1.05; p = 0.01). The rate of bike lane excursions significantly decreased by 68 % for the wide bike lane on the curved mid-block section of the road compared to the standard width bike lane (IRR = 0.32; 95 % CI = 0.11–0.88; p = 0.03). Riders, aged 26–40 years, had a significant increased rate of 8.72 excursions than riders aged 18–25 years (IRR = 8.72; 95 % CI = 3.32–22.89; p
Presentation
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Background: Infrastructure layout has often been shown to influence cyclists’ as well as car drivers’ behaviour towards cyclists in direct ways in traffic observations (Chapman & Noyce, 2014; Chuang et al., 2013; Dozza et al., 2016; Harkey & Stewart, 1997; Love et al., 2012; Morrison et al., 2019; Metha et al., 2015; Parkin & Meyers, 2010; Pulugurtha & Thakur, 2014; Shackel & Parkin; 2014; Stewart & McHale, 2014) as well as in the driving simulator (Huemer et al., 2018), showing that on-street markings for cyclists in some circumstances reduce overtaking distances by car drivers. On the other hand, subjective data of cyclists show that more separation indicated by on-street markings is preferred by them (Hagemeister & Kropp, 2019). In order to inform planning authorities, the present studies examine the effects of different on-street markings on cyclists’ as well as car-drivers’ behaviour. Aim: These two studies test different infrastructure layouts for cyclists in (a) regard to cyclists’ lateral positioning on the street, i.e. their lateral distance to parking cars on the right kerbside, as well as cyclists’ judgements about these layouts concerning subjective safety and perspicuity in a cycling simulator study, as well as (b) car drivers’ behavior and towards cyclists on these infrastructure layouts as well as their opinions about the layouts in a subsequent driving simulator study and (c) car drivers’ behavioral influence on subsequent traffic flow in the second experiment. Method: In the firsts study N=50 cyclists will be riding 300m of 18 different infrastructure layouts in the cycling simulator in randomized order in a within subject design. For cyclists, lateral distance to parking cars on the right kerb as well as subjective ratings concerning safety and perspicuity is recorded. Data collection of this first part has just started and is expected to be over at the end of February. In the second study N=50 car drivers will be driving each infrastructure layout in randomized order in a within subject design as well, but in the driving simulator with simulated cyclists that may or may not be overtaken by these drivers. Data collection for the second study will start at the end of the first one as cyclists’ positions there will inform the simulated cyclists’ lateral position in the second study aiming it to be realistic. For car drivers, driving behaviour, it will be recorded regarding if and when they overtake cyclists, their lateral distance and speed when overtaking the cyclists as well as subjects’ behavioural consequences on subsequent traffic flow in the simulation. Car drivers’ subjective ratings concerning safety and perspicuity will be recorded as well.
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Unlike door crash accidents predominantly involving bicycles in Australia, the UK, and other Western countries, cases in Taiwan are far more fatal as they usually involve motorcycles. This is due to the unique anthropogeography and transportation patterns of Taiwan, particularly the numbers of motorcycles being twice that of cars. Both path analysis and multivariate logistic regression methods were adopted in this study. The multivariate logistic regression analysis results have shown that the main risk factors causing serious injuries in door crashes include winter, morning, male motorcyclists, heavy motorcycles, and the left sides of cars. Regarding the gender differences in motorcyclists, it appears that female motorcyclists have higher door crash accident rates, while the odds of severe injury and fatality in male motorcyclists are 1.658 times greater than that of female motorcyclists. The risk factors derived from the multivariate logistic regression analysis were further discussed and analysed. It was found that the causes of serious injuries and deaths stemming from door crashes were related to the risk perception ability, reaction ability, visibility, and riding speed of the motorcyclists. Therefore, suggestions on risk management and accident prevention were proposed using advocacy through the 3E strategies of human factors engineering design.
Article
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Cyclists are often passed by motor vehicles in low-cycling countries where most riding occurs on roads. When passing events occur, the lateral passing distance (LPD) between motor vehicles and bicycles is critically important for objective and subjective safety. This systematic review identified 42 papers reporting 36 independent studies of LPD. Seven papers reported sufficient information to be included in meta-analyses for four different variables; road width, speed limit, on-road bicycle lanes compared to no bicycle lanes and bus versus car. The meta-analyses showed significant positive relationships between LPD and road width, and between LPD and speed limit; and smaller LPDs when cyclists were passed by buses rather than cars. The effect of on-road bicycle infrastructure was inconsistent. Studies that considered cyclist factors such as gender or type of cyclist showed mixed results. Seven out of eight studies found that the closer the cyclist rode to the kerb, the larger the LPD. Lastly, the passing strategy chosen by drivers (accelerative or flying) also showed mixed results. The results of the review are consistent with the predictions of the Multiple Comfort Zone model which predicts that the distance a driver leaves between their vehicle and other road users will be based on attempting to maintain their own comfort zone. Other motor vehicles pose a greater risk to drivers than bicycles, therefore the distance a driver chooses between their vehicle and a bicycle may be compromised if there are other vehicles present or if the available travel space is restricted. As governments around the world grapple with increasing health costs caused by physical inactivity, bicycle riding is being encouraged. Given the importance of the passing manoeuvre for cyclist safety, when designing infrastructure to foster cycling, factors that influence LPD should be considered.
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This study examined the potential effect of special paintings of shared lane markings (super sharrows) on a number of operational and safety performance parameters for cyclists and motor vehicles. These performance parameters were used to assess pretreatment and posttreatment behavior when cyclists and motor vehicles were near one another. The performance parameters were ( a) rate of lane change maneuvers performed by vehicles in the presence as well as the absence of cyclists and ( b) lateral spacing between cyclists, vehicles, and curb edge. In general, the main objectives of this treatment were ( a) providing cyclists with comfort by allowing them to ride in the middle of the travel lane and ( b) promoting safe passing by motor vehicles. The effect of the super sharrows on cyclists and motor vehicles was analyzed with statistical analysis by comparing pretreatment and posttreatment conditions. The key findings are as follow: ( a) super sharrows had an effect on motor vehicle lane change maneuvers, represented by an increase in the percentage of motor vehicles that changed from the right lane (location of super sharrows) to the left lane with the presence of a cyclist on the right lane; ( b) the number of motor vehicles that changed from right lane to left lane and back to right lane in both full and partial encroachment into the left lane decreased; ( c) the number of the motor vehicle lane change maneuvers from left to right lane decreased; and ( d) cyclists were found to be riding farther from the right curb with the presence of the super sharrows.
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Problem and method: This paper takes a critical look at the present state of bicycle infrastructure treatment safety research, highlighting data needs. Safety literature relating to 22 bicycle treatments is examined, including findings, study methodologies, and data sources used in the studies. Some preliminary conclusions related to research efficacy are drawn from the available data and findings in the research. Results and discussion: While the current body of bicycle safety literature points toward some defensible conclusions regarding the safety and effectiveness of certain bicycle treatments, such as bike lanes and removal of on-street parking, the vast majority treatments are still in need of rigorous research. Fundamental questions arise regarding appropriate exposure measures, crash measures, and crash data sources. Practical applications: This research will aid transportation departments with regard to decisions about bicycle infrastructure and guide future research efforts toward understanding safety impacts of bicycle infrastructure.
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The 2009 manual on uniform traffic control devices (NIVKD) includes a new bicycle safety device: The shared lane marking. Also known as a "sharrow," this pavement marking is placed in a lane shared by motorists and bicyclists to encourage bicyclists to ride at the safest position and to alert motorists to the possible presence of bicyclists.
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In 2013, the City of Oakland, California, implemented a green shared lane (i.e., super sharrow) treatment, which consisted of a continuous band of green color on the pavement in conjunction with shared lane markings (i.e., sharrows) as an experimental traffic control device. The implementation was an attempt to improve traffic operations on a multilane urban roadway frequented by cyclists but for which geometric constraints prevented installation of dedicated bicycle lanes. The purpose of the experiment was to promote (a) safe and legal lane positioning by cyclists and (b) safe and legal passing by motorists. Through statistical analysis, the effects of the green band (i.e., green shared lane) on user behavior were isolated for comparison with the effects of no bikeway striping and standard sharrows. The key findings were (a) the green shared lane led cyclists to ride farther from parked cars (i.e., outside of the door zone) than they did with standard sharrows; (b) standard sharrows and the green sharrow lane led motorists to shift more often from the right to the left travel lane than they did with no bikeway striping; (c) the average passing distance for motorists who overtook cyclists did not change significantly; (d) the percentage of motorists who left 3 ft or more when they passed decreased with the presence of the green sharrow lane; and (e) the green shared lane had no negative operational effect on auto operations, auto speed, or transit speed.
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Growing awareness of environmental and public health problems associated with motorized transportation has led to a recent effort to promote nonmotorized modes of travel. Previous studies have shown that facility design plays a large role in encouraging bicycling. With the aim of defining the roadway configurations that lead to safe motorist and bicyclist behavior, this research examines the impact of design elements, including the type and width of the bicycle facility, the presence of adjacent motor vehicle traffic, parking turnover rate, land use, and the type of motoristbicyclist interaction. Observational studies conducted at 48 sites in three large Texas cities characterize bicyclist and motorist behavior through lateral position measurements and instances of motorist encroachment on an adjacent lane. These observations were used to build two multivariate regression models and allowed for direct site-to-site comparisons. Notable results include the observation that bicycle lanes create a safer and more predictable riding environment relative to wide outside lanes, and that the provision of a buffer between parked cars and bicycle lanes is the only reliable method for ensuring that bicyclists do not put themselves at risk of being hit by opening car doors.
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This analysis uses data from a survey of Toronto commuter cyclists that collected information regarding accident history as well as regular commute route to work or school. By relating the route information of the 1196 respondents to facility attributes in a Geographic Information System (GIS), defensible estimates of travel exposure on roads, off-road paths and sidewalks were developed. The rate of collision on off-road paths and sidewalks was lower than for roads. The relative rates for falls and injuries suggest these events are least common on-road followed by off-road paths, and finally most common on sidewalks. The rate of major injuries, an injury that required medical attention, was greatest on sidewalks and the difference between paths and sidewalks was negligible. These rates suggest a need for detailed analysis of sidewalk and off-road path bicycle safety. The absolute event rates per bicycle kilometer were found to be between 26 and 68 times higher than similar rates for automobile travel, re-confirming the urgent bicycle safety crisis. Examination of rates for sub-groups of cyclists suggest that experience is an important factor in bicycle safety. The same survey conducted in Ottawa, Canada found event rates much lower than Toronto. This result may confirm urban form, traffic levels and attitude do affect bicycle safety. The analysis also demonstrates a successful method to quantify bicycle travel exposure information and should be considered for further use as complement to other existing techniques.
Bicycle Facilities Adjacent to On-Street Parking: A Review of Crash Data, Design Standards, and Bicyclist Positioning
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More Than Sharrows: Lane-Within-a Lane Bicycle Priority Treatments in Three U.S. Cities
  • P G Furth
  • D M Dulaski
  • D Bergenthal
  • S Brown