Conflicts between motor vehicle and cyclists at a signalized intersection were characterized in this study using an objective conflict indicator; post encroachment time (PET). A total of 384 conflict events for PET (0, 3] seconds between cyclists and vehicles were analyzed in this study. An automated video analysis technique was developed to measure the PET between cyclists and motor vehicles. The results of the conflict analysis showed that the average absolute error of PET between the frame count measurement (MFCM) and automated measurement (AM) methods was 0.12 s and the standard deviation was 0.10 s. The evaluation result showed that the coefficient of determination between the AM and MFCM methods was found to be 0.938 and there was a very good agreement in the PET classification of individual conflicts between the MFCM and AM methods. This study includes procedures to better interpret the conflict point of the motor vehicle and the cyclist in an automated manner (based on the geometry of the bounding box and direction of the travel), which appears to be a contribution for the analysis of cyclist – motor vehicle collisions.
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.
The City of Ottawa has been investigating design solutions to facilitate the addition of cycling facilities, while maintaining parking, to roadways with limited right-of-ways. A pilot project to install advisory bike lanes was initiated. The purpose of this study is to determine how new pavement markings (advisory bike lanes) influence cyclist and motorist interactions and positioning, especially with respect to the distance between motorists and cyclists when passing. The study presents a before–after evaluation of two contrasting pavement indications. Video data were collected in two phases (pre- and post- treatment); each phase consisted of two different days. A number of safety performance parameters were used to assess whether safer conditions existed after the new treatment was installed: (i) the lateral distance between the motor vehicle and cyclist, (ii) the lateral distance between the cyclist and curbside edge/cyclist and buffer edge line, and (iii) the speed of the cyclist and motor vehicle. The findings indicate that the advisory bike lanes created more favorable conditions for cyclist safety and for motor vehicle compliance. These findings are (i) motorists passed cyclists with a greater lateral separation distance, (ii) cyclists positioned themselves further from parking edge line and rode in the middle of the bike lane, (iii) motor vehicle traveling speed decreased (the 85th percentile speed decreased by 5.2% after the installation of the advisory bike lane), and (iv) average cyclist speed increased (the average cyclist speed increased by 7.7% after the installation of the advisory bike lane).
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