Issue link: http://uwashington.uberflip.com/i/903202
22 Pacific Northwest Transportation Consortium • Project: Evaluation of Motorcyclists and Bikers' Safety on Wet Pavement Markings • PI: Somayeh Nassiri (WSU), snassiri@wsu.edu For this project, there will be multiple different field tests of the pavement markings to determine the safety evaluation. There will first be a qualitative bike and motorcyclist rider evaluation survey to determine the slippage of marked roadways under different conditions. The same locations will also be tested using a British Pendulum Tester (BPT) to collect quantitative data. The qualitative and quantitative data will then be compared using field data. Square one-foot slabs will also be tested in the laboratory using the BPT as seen in Figure 1. Each of the tests for the qualitative and quantitative data will be evaluated under different degradations of the pavement markings as well as different surface conditions (dry, wet, and ice). The degradations will be evaluated in the field to find different levels while the laboratory testing will use a wheel abrasion tester to degrade the markings to different levels. • Project: A Data Driven Safety Assessment of Various Left Turn Phasing Strategies • PI: Ali Hajbabaie (WSU), ali.hajbabaie@wsu.edu Protected-permissive left turn phases have potential to improve traffic operations by allowing more vehicles to complete their left turns during the permissive phase especially in off-peak hours; however, their safety is perceived to be less than protected-only left turn phases. As such, assessing the safety of protected-permissive left turn phases with FYA is needed before implementing them in the field. Doghouse displays accommodate permissive left turn movements during a circular green signal without an FYA. As a result, doghouse displays may create some confusions among drivers as a circular green signal indicates the allocation of the right-of-way while left turning vehicles must yield to the opposing traffic during the permissive phase with a circular green signal. The safety impacts of doghouse displays need to be assessed and compared to that of FYAs before making a decision to use them. Finally, signal plans may change from a protected-permissive with FYA to a protected-only phase in different times of the day, based on traffic conditions. There is evidence showing that protected-permissive phases with FYA may contribute to more crashes during off-peak periods due to driver confusion. It is needed to identify if changing the phase plane from of time of the day to another creates confusion among drivers. This research will use a data-driven methodology to assess the safety of the aforementioned signalization strategies. The results of this research will help decision makers to select a more suitable signal phasing plan/display under various operational conditions. Specific objectives are: 1. Compare the safety of protected left turns to protected-permissive left turns with FYA, 2. Compare the safety of doghouse displays to four section vertical displays with Flashing Yellow Arrow (FYA), and 3. Assess the safety of including FYA phases in protected-permissive left turns at different times of the day to identify if it creates driver confusion. "Public transit and pedestrian safety has gained increasing attention. Bus-to-pedestrian collisions often result in injuries, fatalities and insurance losses. For example, according to Washington State Transit Insurance Pool (WSTIP), a large portion of the collision-related transit losses are with pedestrians in Washington region." — Yinhai Wang (UW)