Increasing driver yielding and pedestrian signaling with prompting, feedback, and enforcement

The effects of an intervention package on drivers' yielding to pedestrians and on pedestrians' signaling their intention to cross the street were assessed using a multiple baseline design. The intervention, which consisted of publicly posted feedback on the percentage of motorists yielding to pedestrians, small signs prompting pedestrians to engage in appropriate crossing behavior, and an enforcement program involving the use of warning tickets and feedback fliers, was sequentially introduced on two streets. The intervention more than doubled the percentage of motorists yielding to pedestrians and increased the percentage of pedestrians signaling their intention to cross the street to over 13% from a baseline level of less than 1%. Near misses involving pedestrians decreased by more than 50% on the narrower of the two streets.     

The effects of prompting and feedback on drivers' stopping at stop signs

Complete stops at a high-traffic intersection on the campus of a public university were increased with a prompting and consequence intervention. Data were collected at two opposing stop signs (Stop A and Stop B); however, the intervention was implemented only at Stop A. During the intervention, a volunteer stood next to Stop A holding a poster that read, "Please Stop--I Care," with "Thank You For Stopping" on the reverse side. The poster was held by the volunteer so that drivers approaching Stop A could read the sign. Drivers approaching Stop B could see the volunteer but could not read the sign. When vehicles approaching Stop A made a complete stop, the volunteer flashed the "thank you" side of the poster to the driver. The strategy was evaluated using a multielement design. The intervention increased stops completed at Stop A from a baseline average of 13% to an intervention average of 52%. Stop B also showed improved stopping, from a baseline average of 6% to an intervention average of 28%. Data showed no relation between complete stops made and the drivers' use of turn signals and safety belts.     

Examining the efficacy of improved traffic signs and markings at flashing-light-controlled grade crossings based on driving simulation and eye tracking systems

The majority of the collisions at grade crossings occurred at flashing-light-controlled grade crossings. Understanding drivers’ behaviors and visual performances in the process of approaching the crossings is the foundation of improving crossing safety. This study aims at utilizing driving simulation and eye tracking systems to investigate the efficacy of improved traffic signs and pavement markings (PSM) at flashing-light-controlled grade crossings. The improved signs and markings were modeled in a driving simulation system and tested with a series of flashing light trigger time (FLTT) ranging from 2 s to 6 s with 1 s interval increment. Foggy conditions and drivers’ genders and vocations were considered in experiment design. Thirty-six fully-licensed drivers between 30 and 48 years participated in the experiment. Several eye-movement and behavioral measures were adopted as reflections of the subjects’ performances, including the first fixation time on signs and signals and distance to stop line, total fixation duration, compliance rate, stop position, average speed at the stop line, maximum deceleration rate and brake response time. Results showed that compared with traditional grade crossings signs and pavement markings, drivers could perceive signs timelier and fixate on the flashing-light signal earlier in PSM, especially in the scenarios of earlier FLTTs. The improvement in fixation performance and sign design contributed to a higher stop compliance rate. Importantly, it was found that drivers would hesitate to decide whether to stop or cross facing with flashing red lights, which is similar to the dilemma zone of roadway intersections. Drivers were more likely to fall into the dilemma zones when FLTT was <4 s. When FLTT was 2 s, it was particularly difficult to stop in front of the stop line. Moreover, under a foggy condition, drivers had a difficulty in searching signs and had a longer brake response time compared with a clear condition. For the characteristics of drivers, male drivers had longer fixation duration on signs than females. Professional drivers had a higher maximum deceleration rate compared with non-professional drivers. Above findings implied that improved traffic signs and markings would have a potential to improve traffic safety and deserve a field implementation in the future.     

Fuzzy sets to describe driver behavior in the dilemma zone of high-speed signalized intersections

The Type II dilemma zone describes a segment of road on the approach to a signalized intersection where, if occupied by a motorist presented with the circular yellow indication, is likely to result in a motorist having difficulty deciding to stop at the stop line or proceed through the intersection. This phenomenon results in increased frequency of three failure conditions: rear-end collision at the stop line (excessive deceleration rates), the more severe right-angle crashes in the intersections, and left-turn head-on collisions (both resulting from incorrect estimates of clearance time). A more effective boundary definition for Type II dilemma zones could contribute to the safe design of signalized intersections. The prevailing approaches to dilemma zone delineation include the consideration of the vehicle’s travel time to the stop line or the driver’s likelihood of stopping at a particular distance from the stop line. The imprecision of the driver’s perception of speed and distance suggest that fuzzy logic may contribute to the identification of the Type II dilemma zone boundaries. A fuzzy logic (FL) model was constructed and validated from driver’s empirically observed behavior at high-speed signalized intersections. The research resulted in an increased understanding of the phenomenon which, when applied to the timing of signals and the placement of vehicle detection, can improve the overall safety of signalized intersections.     

Safer driver responses at intersections with green signal countdown timers

Traffic signal countdown timers (TSCTs) are innovative, practical, and cost effective technologies with the potential to improve safety at signalized intersections. The purpose of these devices is to assist motorists in decision-making at signalized intersections by providing them with real-time signal duration information. This study examines US driver responses in the presence of a green signal countdown timer (GSCT) and the implications those responses have on intersection safety. A driving simulator study was conducted to record driver responses to virtual GSCTs. Fifty-five participants (32 male and 23 female) responded to 1100 simulated traffic signals, half of which had GSCTs. A predictive model was developed and validated to estimate the change in driver’s probability to stop at different distances from the stop line in the presence of a GSCT. The presence of a GSCT increased average driver stopping probability in the dilemma zone by 13.10%, while decreasing average driver deceleration rates by 1.50 ft/s². These results suggest that GSCTs may contribute to improved intersection safety in the US.     

Effects of listening to music, and of using a handheld and handsfree telephone on cycling behaviour

The effects of listening to music on cycling behaviour were evaluated. Twenty-five participants completed a track on a bicycle while listening to music with two standard earbuds, with one earbud, and with two in-earbuds. Conditions with high tempo music and loud volume were also included in the experiment, as were two mobile phone conditions, one in which participants operated the phone hand held and one handsfree condition.Cycle speed was not affected by listening to music, but was reduced in the telephone conditions. In general the response to auditory signals worsened when participants listened to music, in particular when listening with in-earbuds loud auditory stop signals were missed in 68% of the cases. However, when listening with only one standard earbud performance was not affected. In the conditions when participants listened to high volume and to high tempo music, the auditory stop signal was also heard in significantly fewer cases. Completing a task on the mobile phone, using both handheld and handsfree sets, resulted in increased response time to an auditory stop signal and also reduced overall auditory perception. Furthermore, handsfree operation only had minor advantages opposed to hand held operation, with only response time to an auditory stop signal resulting in faster performance. This is likely to be related to the fact that both hands could be used for braking.It is concluded that listening to music worsens auditory perception, in particular if in-earbuds are used. Furthermore, both handheld and handsfree operation of mobile phones has a negative effect on perception, potentially forming a threat to cyclist traffic safety.     

An evaluation of the effectiveness of countermeasures for improving the safety of dilemma zones: A driving simulator study

The main objective of this driving simulator study is to analyze the behavior of the driver at the start of the yellow signal of a signalized rural intersection and identify the most effective countermeasures for tackling the dilemma zone, namely an area on the intersection approach where vehicles at the start of the yellow phase can neither safely stop before the stop line nor cross the intersection. The following countermeasures were tested in the study on a sample of 48 drivers: green signal countdown timers, GSCT (C₁); a new pattern of vertical and horizontal warning signs (C₂); and an advanced on-board driver assistance system based on augmented reality (AR) and connected vehicle technologies (C₃). These countermeasures were tested and compared to a baseline condition (B) where no countermeasures were applied. Based on the results of this study, the C₂ and C₃ countermeasures have proven to be valid tools for reducing driver indecision when approaching signalized intersections at the start of the yellow signal. In fact, using C₂ and C₃, the length of the dilemma zone was equal to 30 m and 36 m, respectively, with a reduction of about 50%, as compared to the baseline condition (B). Moreover, a reduced number of false behaviors was recorded, as well as a greater consistency in driver decision-making behaviors. Conversely, the C₁ countermeasure did not lead to a significant improvement in the dilemma zone: an unnecessary increase in early stop rates was recorded, resulting in reduced intersection efficiency and operations.     

Community-Engaged Neighborhood Revitalization and Empowerment: Busy Streets Theory in Action

Busy streets theory predicts that engaging residents in physical revitalization of neighborhoods will facilitate community empowerment through the development of sense of community, social cohesion, collective efficacy, social capital, and behavioral action. Establishing safe environments fosters positive street activity, which reinforces neighborhood social relationships. A community-engaged approach to crime prevention through environmental design (CE-CPTED) is one promising approach to creating busy streets because it engages residents in collaborative interactions to promote safer environments. Yet, few researchers have studied how CE-CPTED may be associated with busy streets. We interviewed 18 residents and stakeholders implementing CE-CPTED in Flint, Michigan. We studied three neighborhoods with different levels of resident control over CE-CPTED. Participants described how CE-CPTED implementation affected their neighborhood. Participants from all three neighborhoods reported that CE-CPTED was associated with positive street activity, sense of community, and collective efficacy. Participants from neighborhoods with higher resident control of CE-CPTED reported more social capital and behavioral action than those from neighborhoods with less resident control. Our findings support busy streets theory: Community engagement in neighborhood improvement enhanced community empowerment. CE-CPTED that combines physical revitalization with resident engagement and control creates a potent synergy for promoting safe and healthy neighborhoods.     

Effects of speed display signs on driving speed at pedestrian crossings on collector streets

This study was designed to evaluate the short- and long-term effects of speed display signs on driving speed at pedestrian crossings in a low-speed (40 km/h) urban environment. Driving speeds were compared 1 week before installation, after installation (1 week; 1 month; 3 months; 5 months) and 1 week after removal. The main results showed that the speed displays decreased the mean speed by 0.5–2.9 km/h, which translates to a 4–22% drop in pedestrian fatality risk. Furthermore, there was a drop in the proportion of speeding vehicles and approaching speed of individual vehicles. The decrease in speed persisted over time, suggesting that speed displays may reduce speeds in the long term. In conclusion, installing speed displays at pedestrian crossings on collector streets reduces driving speeds and could contribute to the safety of pedestrians.     

Improved driver behaviour at bus stops on local roads: Comparison of different treatments

Every day, millions of students use school bus as a mean of transportation to and from schools. Nevertheless, most of the school bus related crashes occur at or near bus stops. The overtaking of stopped school buses during boarding and alighting of students imposes safety risks on students and drivers. This study aims to investigate the impact of three different treatments on driving behavior at bus stops. In total, this study compared four different conditions. Three of them were treatment conditions namely (Red Pavement, Road Narrowing, and smart LED), which were compared with a control condition (i.e., the default bus stop layout without any additional treatments as implemented in the State of Qatar). Each condition was tested for three situations. Situation 1 and Situation 2 were designed with the presence of a stopped school bus on the same and on the opposite travel directions, respectively, while, Situation 3 was designed without any school bus at the bus stop location. A total of 72 subjects participated in the experiment. Generalized Linear Mixed Model (GLMM) was employed to study the impact of several factors on the overtaking/crossing probability of the stopped school bus. In Situation 1, Road_narrowing condition outperformed the other conditions by making 94.3 % of drivers to stop for the bus, while in Situation 2, LED condition performed best by making 48.6 % of drivers stop for the bus that is stopped at the opposite travel direction. Moreover, the LED and Road_narrowing treatments were effective in moderating drivers’ speed behavior, lowering their traveling speed by 5.16 km/h and 5.11 km/h, respectively even in the absence of any bus at the bus stop. Physical road narrowing condition outperformed the other tested conditions, and therefore, can be recommended as a low-cost treatment to improve safety at bus stops. In locations where the implementation of physical road narrowing is not feasible, LED treatment can be used to moderate driver traveling speed and stopping behavior.     

Turning a blind eye to double blind line‐ups

Although psychologists have urged police officers to use double blind line‐up procedures during their investigations, police officers state that these would be difficult to administer and most have been reluctant to implement this change. Four studies examine whether lay people's judgements about the guilt of a suspect vary according to whether a brief written summary of a case described the identification procedure as double blind or non‐double blind. The effects were all small (and almost all non‐significant). Most people do not treat double blind line‐ups differently from non‐double blind line‐ups when assessing the guilt of a defendant. Either police investigators should stop using this biased method or police investigators and others in the judicial system (e.g. jurors, judges) should be informed of this bias when evaluating results from any line‐up. Copyright © 2009 John Wiley & Sons, Ltd.     

Increasing motorist compliance and caution at stop signs.

This study evaluated strategies to improve motorist compliance and caution at three stop‐sign‐controlled intersections with a history of motor vehicle crashes. The primary intervention was a light‐emitting diode (LED) sign that featured animated eyes scanning left and right to prompt drivers to look left and right for approaching traffic. Data were scored from videotape on the percentage of drivers coming to a complete stop and the percentage of drivers looking right before entering the intersection. Observational data were collected on the percentage of right‐angle conflicts (defined as braking suddenly or swerving from the path to avoid an intersection crash). The introduction of the LED sign according to a multiple baseline across the three intersections was associated with an increase in the percentage of vehicles coming to a complete stop at all three intersections and a small increase in the percentage of drivers looking right before entering the intersections. Conflicts between vehicles on the major and minor road were also reduced following the introduction of the animated eyes prompt.     

The effects of a rectangular rapid-flashing beacon on vehicle speed

In 2008, nearly 31% of vehicle fatalities were related to failure to adhere to safe vehicle speeds (National Highway Traffic Safety Administration [NHTSA], 2009). The current study evaluated the effect of a rectangular rapid-flashing beacon (RRFB) triggered by excessive speed on vehicle speed using a combined alternating treatments and reversal design. The percentage of vehicles traveling above 41 mph (66 km per hour) decreased by 20%, and speed distributions showed a shift toward lower speeds during the RRFB condition.     

Factors explaining driver yielding behaviour towards pedestrians at courtesy crossings

Courtesy crossings are pedestrian crossing facilities where drivers are not legally required to stop for pedestrians, but are encouraged to do so by design elements such as stripes, coloured or textured road surfaces, visual narrowings of the carriageway, and ramps. There is little empirical evidence on drivers' behaviour or guidance on how to design these crossings. This paper analysed data for 937 interactions between drivers and pedestrians at 20 crossings across England, comparing driver yielding behaviour at courtesy crossings and at zebras (marked unsignalised crossings, where drivers are legally required to stop); and identifying the design elements associated with yielding behaviour at courtesy crossings. The analysis controlled for crossing stage; characteristics and situation of pedestrians and vehicles; characteristics of the road and site; and time context. Driver yielding behaviour was analysed for each separate traffic lane that pedestrians need to cross. We found that all four design elements considered (stripes, coloured/textured surface, visual narrowing, and ramps) increased the propensity of the first vehicle to stop and of any vehicle to stop. A before-after analysis then showed that adding a new element (stripes) to a courtesy crossing led to an increase in yielding rates from 20% to 97%. Overall, we found evidence supporting the use of multiple design elements in courtesy crossings. We discuss the implications of these findings for transport policy and urban design.     

Cars overtaking cyclists on different urban road types – Expectations about passing safety are not aligned with observed passing distances

Cars overtaking cyclists have been identified as a source of crashes and subjective risk. Several studies investigated the passing distance for different road types. There has been less research concerning cyclists’ expectations concerning the passing distance at different road types. Thus, we aim at contrasting cyclists’ expectations about the passing safety for different speed limits and cycling infrastructures with the passing distances observed at corresponding urban road types. For this purpose, we show participants images of a predefined set of survey zones in a web-based survey, and ask them about the expected passing safety of cars overtaking them when imagining riding their bikes at these locations. We measure the observed passing distances at the same survey zones with a bike-mounted sensor. We find that cars meet the German legal minimum passing distance of 1.5 m in towns in only 30% of all observed events. In 30 km/h speed zones, passing distances at roads featuring dedicated cycling infrastructure (e.g. bike lanes, cycling boulevards) are decreased as compared to those featuring no cycling infrastructure. In contrast, people estimate that the passing safety on roads with dedicated cycling infrastructure is safer than without cycling infrastructure. This effect is even more pronounced on living streets. Situations where oncoming cars (e.g. living streets, ‘opposite’ roads) must be passed in close distance are apparently not perceived as particularly dangerous. Cycling tracks in 50 km/h speed zones increase both the observed passing distance and the corresponding expectations about passing safety. Taken together, the qualitative comparison of the two datasets implies that cyclists’ expectations about cars passing them in a more adequate and safe distance in streets with reduced speed limits and dedicated cycling infrastructure are not justified in light of the actually observed passing distances. Possible explanations for the contradicting patterns could be that cyclists prefer situations where space is explicitly dedicated for bikes, that they account for the anticipated car traffic volume, and that they assume oncoming cars as less dangerous to pass.     

Impact of time pressure on acceleration behavior and crossing decision at the onset of yellow signal

This study investigates acceleration behavior and crossing decision of the drivers under increasing time pressure driving conditions. A typical urban route was designed in a fixed-base driving simulator consisting of four signalized intersections with varying time to stop line (4 s and 6 s) and maneuver type (right-turn and go-through). 97 participants’ data were obtained under No Time Pressure (NTP), Low Time Pressure (LTP), and High Time Pressure (HTP) driving conditions. The acceleration behavior was examined at the onset of yellow signal in four ways: continuous deceleration, acceleration-deceleration, deceleration-acceleration, and continuous acceleration. A random forest model was used to build an acceleration behavior prediction model for identifying the significant explanatory variables based on variable importance ranking. Further, a Mixed Effects Multinomial Logit (MEML) model was developed using the explanatory variables obtained from a random forest model. Additionally, a generalized linear mixed model was incorporated for estimating the likelihood of crossing an intersection by considering all the explanatory variables. A MEML model result revealed that the odds of adopting acceleration-deceleration, deceleration-acceleration, and continuous acceleration instead of continuous deceleration increased by 63 %, 123 %, and 77 %, respectively under HTP driving conditions. Moreover, the likelihood of crossing a signalized intersection increased by 2.73 times and 4.26 times when the drivers were under LTP and HTP driving conditions, respectively as compared to NTP driving condition. Apart from this, time to stop line (reference: 6 s) and age showed negative association with crossing probability. Overall, the findings from this study revealed that drivers altered their acceleration behavior for executing risky driving decisions under increasing time pressure driving conditions.     

‘And what about residential…?’ Re‐conceptualizing residential treatment as a stop‐gap service for youth with emotional and behavioral disorders

The need for residential services for youth with the most intractable emotional and behavioral problems continues to exist despite advances made in developing community‐based systems of care. Residential treatment centers (RTCs), considered one of the most restrictive service settings, have changed little over the years and have not fared well in outcome evaluations. Despite these factors, admissions to RTCs continue to increase. In an attempt to contemporize and bring the RTC more in line with current practice, a stop‐gap model of service delivery is recommended. The stop‐gap model, incorporating evidence‐based practices, is intended to have an immediate and positive impact on the barrier behaviors that keep youths in the most restrictive environments. The twofold goal of the stop‐gap model is to interrupt the youth's downward spiral imposed by increasingly disruptive behavior and, simultaneously, to prepare the post‐discharge environment for the youth's timely reintegration. Strategies for evaluating the effectiveness of the stop‐gap model are recommended. Copyright © 2004 John Wiley & Sons, Ltd.     

Cyclist efficiency and its dependence on infrastructure and usual speed

Bicyclists are a heterogeneous group, with varying abilities, traffic education and experience. While efficiency was identified as an important factor on utility bicycle trips, it might be traded for experienced safety, for example by choosing different pathways in a given situation, or by relinquishing one’s right of way. In a semi-controlled study with 41 participants, a grouping was made according to self-reported riding speed in relation to other cyclists. The participants cycled twice along a 3 km inner-city route, passing four intersections with different priority rules. The cyclists were free to choose how to negotiate the intersections. Speed and the traffic surroundings were recorded via gps and cameras on the bike of the participant and of a following experimenter. For each cyclist, the ‘base’ speed on undisturbed segments was determined as reference. Based on this, the efficiency in different types of intersections was computed per cyclist group. It turned out that infrastructural aspects, cyclist group and the presence and behaviour of interacting traffic influenced cyclist efficiency. Faster cyclists were delayed more when the infrastructure required a stop regardless of the traffic situation, like at a red traffic light or a stop sign. The members of the so-called ‘comfort cyclists’ group were delayed the most in a roundabout with mixed traffic, where many chose to get off their bike and walk. In a society working for equality of access to the transport system, it is recommended to develop solutions that consider and accommodate the behaviours of different cyclist groups when planning bicycling infrastructure.     

The effect of yellow light onset time on older and younger drivers’ perception response time (PRT) and intersection behavior

To understand why older drivers are over-represented in intersection crashes, this study sought to describe the intersection performance of older and younger drivers when traffic lights changed from green to yellow at the last second. Using a moderate-fidelity driving simulator, time to stop line (TSL) at yellow onset was manipulated as drivers approached intersections at 70 km/h (42 mph). Seventy-seven participants, approximately balanced for gender and age group, volunteered from the age categories of 18 to 24, 25 to 35, 55 to 64, and 65+. Driver decisions to stop or go were predicted using a logistic regression model with time to stop line as the single significant predictor. There were no age differences in perception response time (PRT). Older drivers approached intersections at a lower velocity and stopped more accurately than younger drivers. For those drivers who chose to go through the yellow light, speed profiles across the intersection and intersection clearance indicate that older drivers are more likely to be in the intersection when the light changed to red. A PRT of 1.0 s for yellow signal phasing was sufficient for all age groups.     

Safety on the Playground: Mechanisms Through Which Adult Supervision Might Prevent Child Playground Injury

Over 200,000 American children visit the emergency room annually after a playground injury. Among the most promising means to reduce playground injuries is through increased quantity and quality of playground supervision by adults. To implement empirically supported playground supervision interventions, it is essential to understand how supervision prevents injuries. Recent research suggests supervision likely prevents injuries through several different mechanisms; this paper discusses six: (a) Supervisors repetitively teach children playground rules; (b) supervisors recognize and stop children's dangerous behavior; (c) supervisors prevent children from behaving impulsively; (d) the presence of a supervisor causes children to behave differently; (e) supervisors change children's attribution of risk; and (f) supervisors have influence as modelers and persuaders of safe behavior. Theoretical implications for future work and applied implications for the development of playground safety interventions are discussed.