Motorcyclist Braking Performance in Stopping Distance Situations.

Motorcycle braking distance is one of the main components of motorcycle stopping sight distance. Motorcycle braking performance in different situations was not consistent in published literature. This research measured the riders’ braking distances and decelerations to both unexpected and expected objects. For braking maneuvers to an expected object, 89 motorcycle riders released the accelerator and applied the brake as quickly as possible following activation of a light beside the road of both dry and wet pavements. As for an unexpected object, 16 nonalerted subjects were confronted with the need to stop for an unexpected object along the roadway. Vehicle speeds, braking distances, and average deceleration were computed for each braking maneuver. Results showed that the deceleration varied among the riders in which 90% of riders’ decelerations were at least 2.75 m/s2 under wet conditions, whereas 90% of all riders decelerated at least 3.3 m/s2 on dry pavements. Overall, the motorcycle braking distance is more than the braking distance of passenger cars. These findings suggest that in countries where motorcycles are heavily used, their roads should be investigated for provisions of adequate motorcycle stopping sight distance, especially if the roads were designed according to AASHTO guidelines

Level of service model for exclusive motorcycle lane.

The concept of level-of-service (LOS) is meant to reflect the trip quality a traveler will experience on a roadway or other transportation facility. The present paper illustrates a statistical model for estimating motorcycle level-of-service (LOS) at exclusive motorcycle lanes in order to predict riders' perceptions about the service quality. 261 motorcycle riders contributed in a survey and rated the service quality of 500 m segments of exclusive motorcycle lane as it is shown on the scenes which are videotaped from the rider's perspective. Participants were asked to rate (using predefined scores) the service quality of clips on 6 point scale ranging from excellent to very poor after watching 10 video segments. The resulting linear regression model shows that the mean rider rating from motorcyclists' survey had statistically significant correlations with operational and design characteristics (R2=0.62). This method is hoped to provide the means required in order to develop a procedure resulting in specific feedbacks to be effective for exclusive motorcycle lane level-of-service criteria and thresholds

Motorcycle characteristics for sight distance investigation on exclusive motorcycle lanes.

In developing Association of Southeast Asian Nations (ASEAN) countries, the motorcycle is a popular means of transportation because it is cheap and provides flexible door-to-door mobility. However, motorcyclists are also highly involved in road accidents. Separating motorcycles from other vehicles in traffic by providing motorcycle lanes is a good engineering measure to improve the safety of motorcyclists. In designing motorcycle lanes, considerations of geometrical elements such as horizontal and vertical curve lengths, stopping distances, and passing sight distances are essential. This study attempts to quantify the eye levels and head levels of motorcycle riders and motorcycle headlight and taillight height characteristics that influenced these geometrical elements. Characteristics of the motorcycles observed along the existing exclusive motorcycle lanes in Selangor state of Malaysia were transcribed from a camcorder, using reference dimension. Findings recommend a design motorcycle eye height of 1,350 mm (5th percentile), headlight height of 800 mm (5th percentile), and taillight height of 625 mm (5th percentile). A motorcyclist height of 1,525 mm (10th percentile) is recommended for the design of sight distance. Recommended heights reduce the cost of motorcycle lane construction with demonstrated safety compared with the current criteria

Motorcyclist rear brake simple perception-response times in rear-end collision situations

Objective: The purpose of this study was to determine the baseline motorcycle riders’ perception–response times (PRTs) in an expected object braking task and to determine the significant difference between PRTs of older and younger riders. Methods: Fifty-nine participants sat on their motorcycles in exactly the same way as they would when riding and then they awaited activation of the taillights of the passenger car (parked) in front of them. PRTs of the motorcyclists were transcribed from the camcorder when the riders hit the brakes as quickly as possible following the activation of the car's brake lights. Results: Results of PRT were calculated by taking the average of both male and female older and younger riders. The study demonstrates that the mean and standard deviation of the motorcycle baseline PRTs are 0.44 and 0.11 s, respectively. Riders’ age and gender were not found to be significant variables for PRT. Conclusion: The mean of baseline perception–reaction time of motorcycle riders is smaller than that of passenger car drivers. If traffic facilities are designed based on passenger car drivers’ simple perception–reaction times where drivers are generally more alert (for example, in traffic signal design), they can provide the required PRT for motorcyclists. This suggests that the utilization of more powerful brake lights on motorcycles could be highly effective for preventing rear-end motorcycle collisions

Evaluation of demand for different trip purposes under various congestion pricing scenarios

Cordon pricing is an effective policy to alleviate congestion and manage travel demand in city centres. However, different responses among road users to certain policies are inevitable. This paper presents a study evaluating the possible consequences of cordon and parking pricing on road users with different trip purposes, i.e., workers and non-workers. Different models have been developed and calibrated with data from the central business district of Mashhad, Iran, using revealed and stated preference methods. The analysis of the interviewee responses to the hypothetical situations shows that workers comprise the dominant proportion using each mode of travel to the Mashhad CBD. The commuters were provided with alternative choices, and their preferences were examined using multinomial logit. The results show that the cost-based policy such as parking and cordon pricing is good to reduce congestion as it affects workers, but the impact is more evident for non-workers travelling to the CBD. Furthermore, the model suggests that workers are more likely to shift mode in response to changes in travel time. The model was also developed to obtain different willingness-to-pay measures, which indicate that workers have a greater willingness to pay for parking and cordon pricing than non-workers

Relationship between the preference and perceived restorative potential of urban landscapes.

This study presents the relationship between "perceived restorative potential" (PRP) and "preference" for an environment with respect to their relationship with the restorative components outlined by attention restoration theory (ART) in two categories: urban built landscape (UBL) and urban natural landscape (UNL). In this experimental study, 120 participants from University Putra Malaysia (Serdang, Malaysia) rated four restorative components, the PRP and "preference" of 24 color slides depicting UBL and UNL scenes. The results showed that "preference" and PRP was moderately correlated in UNL and UBL. "Compatibility" was found to be the most influential variable among all the restorative components in explaining PRP and "preference" in both UNL and UBL. However, "fascination" appeared to be the second most significant predictor of "preference" in UNL, whereas "being away" was the second most significant predictor of PRP in UNL. Furthermore, "coherence" predicted "preference" but it did not predict PRP in UNL. "Being away" and "coherence" were distinct components of PRP and "preference" and of UNL and UBL

Effects of Traffic and Road Factors on Motorcycling Safety Perception.

In Malaysia and other developing Asian countries, the over-representation of the motorcycle population in mixed traffic results in a high number of motorcyclist casualties and fatalities. As a result, by providing a safer environment for motorcycling, the key problem of road accidents would be minimised. Therefore, this study aims to examine the effects of vehicle speed, traffic volume and lane width on mixed traffic conditions. Each of the 60 motorcyclists who took part in this study watched 12 video clips and saw six photographs of road scenes recorded from a number of sites, and rated their perceived safety related to the three variables. This study found that the perceived safety of motorcycling is associated with these three factors (p < 0·01) and motorcycling safety would decrease under higher vehicle speed, heavier traffic volume and narrower lane width. Segregating motorcycles from mixed traffic is one engineering option to address motorcycling safety

Motorcycle - stopping sight distance model for geometric design of exclusive motorcycle lanes

In developing ASEAN countries, motorcycle is a popular transport mode because it is cheap and provides flexible door-to-door mobility. But motorcyclists are also highly involved in road crashes. Separating motorcycles from other vehicles in traffic by providing motorcycle lanes is a good engineering measure to improve safety of motorcyclists. In designing the motorcycle lanes, designing of geometrical elements such as the horizontal and vertical curve lengths to provide of adequate stopping sight distance at every point along the roadway are essential. There are few studies on motorcycle characteristics, but none of them addressed the safe stopping sight distance in the geometric design of motorcycle lanes.Stopping sight distance is calculated using basic principles of physics and relationships among the various design parameters. The majority parameters effects on stopping sight distance are: (i) vehicle characteristics, (ii) driver perception response time, and (iii) driver deceleration rate. This research consists of four different field studies that were undertaken under controlled testing environments for the different aspects that make up the components of the motorcycle stopping sight distance. (i) Motorcycle characteristics, which in study 1 collected real world data to construct a cumulative distribution of rider eye, motorcycle headlight, taillight and motorcyclist head heights as determined by a current motorcycle fleet in Malaysia. Characteristics of the motorcycles observed along the existing exclusive motorcycle lanes in Selangor state of Malaysia were transcribed from a camcorder, using reference dimension. (ii) Motorcyclist Braking Performance, which consisted of three different field studies to obtain riders perception response time, riders deceleration ratio (braking distance). Study 2, tested a rider’s simple perception response time. In this study participants sat on their motorcycles exactly the same way they do while riding and then they awaited activation of the taillight passenger car (parked) in front of them. Perception response times of the motorcyclists were transcribed from camcorder when the riders hit the brakes as quickly as possible following the activation of the car brake light. Study 3 and 4 evaluated rider braking performance including rider perception response time, braking performance and deceleration to an expected and unexpected object on the road. In this study 3, participants rode motorcycle and released the accelerator and applied brake as quickly as possible following activation of a light by the roadside. Study 4, measured rider braking performance when unalerted riders were confronted with the need to stop for an unexpected object that suddenly appeared in the roadway. The motorcycle characteristic study found that all 525 motorcyclist eye heights are higher than the AASHTO 2004 design value of 1,080 mm. It is noted that the 5th percentile driver eye level height is 1,350 mm while the 10th percentile motorcyclist eye level is 1,367 mm. The 5th and 10th percentile motorcycle headlight heights are 800 mm and 880 mm respectively and the 5th and 10th percentile motorcycle taillight heights are 625 mm and 634 mm respectively. The results of braking performance studies for rider simple perception response time show that the mean and the standard deviation of the motorcycle simple PRT are 0.44 sec and 0.11 sec respectively. The mean perception response time to expected and unexpected object scenario is 0.71 sec and 1.25 sec respectively. The 95th percentiles unexpected object perception response time was 2.12 sec. The findings from these studies indicated that most riders are capable of responding to an unexpected object in the roadway in 2.5 sec or less. The results of braking performance studies for rider deceleration and braking distance show that the 90 percent of all riders chose deceleration of at least 3.3 m/s2 on dry pavements. The study found that most riders chose decelerations that are greater than 2.75 m /s2. These decelerations are within riders’ capabilities to stay within their direction and maintain steering control during the braking maneuver on wet surfaces. Overall, this research proposed a motorcycle stopping sight distance model based on motorcycle characteristics, motorcyclist capabilities and performance in response to an expected and unexpected object along the exclusive motorcycle lanes. Results of this research are not only useful for eometric design of exclusive motorcycle lanes but can be used for geometric design of roads in countries with high motorcycle volumes

Drivers’ Speeding Behavior in Residential Streets: A Structural Equation Modeling Approach

Speeding in residential areas is a rampant high-risk driving behavior that occurs worldwide. This study investigated the intention and behavior of speeding in residential streets (with a speed limit of 30 km/h) in Iran based on the Theory of extended Planned Behavior (TPB). A total of 480 participants filled out the TPB-based questionnaire online. Nine different factors were identified by exploratory factor analysis. The interrelationship of these factors, as well as their connection with speeding intention and behavior, was analyzed using the Structural Equation Modeling (SEM) method. The results suggested that the adoption of the extended TPB framework to identify factors related to speeding in residential areas was effective in predicting speeding intention and behavior. Affective attitude, descriptive and personal norms, perceived behavioral control, habits, and specification of residential streets were direct predictors of speeding intention. The intention was also strongly associated with speeding behavior in residential areas, serving as the only factor that directly predicts speeding behavior. The two factors of specification and facilities were also significantly related to speeding behavior on residential streets. The results of this study can have positive implications for preventing and reducing crashes on residential streets