Effectiveness of countdown pedestrian systems in downtown San Diego

Includes bibliographical references (p. 45-46)In California, 6,957 pedestrians were killed during 2000 to 2009, resulting in a fatality rate of 2.0 deaths per 100,000 residents. Approximately one quarter of all fatalities occurs at urban intersections, and the main cause of fatalities is improper crossing. Pedestrians' misunderstanding of pedestrian signal indications at crossings is identified in the literature as a contributing factor to improper crossings. To address this problem and potentially increase the safety at signalized intersection crossings, pedestrian countdown signals were created by incorporating a countdown timer that is displayed simultaneously during the flashing 'DON'T WALK' (FDW) interval. Countdown pedestrian signals (CPS) are increasingly used as a device for improving safety at signalized intersections the timer counts down the number of seconds remaining until the display of the solid 'DON'T WALK' (DW) interval. It has been assumed that this signal design leads to a higher level of pedestrian safety by enabling pedestrians to make better crossing decisions with the added information. That prompted a research project reported in this thesis. A before study was performed on an intersection in downtown San Diego in 2005. An after study of the same pedestrian countdown signal was conducted. That intersection had high pedestrian and vehicular traffic volumes. Pedestrian population was diversified, giving an opportunity to look closer at those groups who are most likely to violate the established crossing rules. The data was collected from August 10, 2009 to August 27, 2009, using a videotaping that simultaneously captured pedestrian and the corresponding traffic signal indications. Over the course of the study, a total of 5,504 pedestrians were observed. Major violators are younger males, runners and bicyclists and they together committing 58.6% Violations of total pedestrian violations. The runners and bicyclists are committing Violation Type 4 (illegal entry, illegal exit) in 38.2% of all their crossing episodes and Violation Type 2 (illegal entry, legal exit) in 16.1% of their crossing episodes. Auto traffic does effect the pedestrian violations. On 2nd avenue (short crossing) with higher auto-gap, more violations were recorded as compared to long crossing with lower auto-gap. Another factor influencing the relatively high violation rate on the short crossing is the problematic designs of the deficient length of flashing don't walk on that approach. More violations were recorded during peak official hours than during the next off-peak hour, but the difference was not statistically significant. Violations on short crossing with less auto traffic are consistent. Pedestrian adjust their speed to be on safe side to finish crossing by observing countdown timer on long crossing with higher auto traffic as compared to short crossing with lower auto traffic. Countdown pedestrian signals appear less effective in places where there is small crossing distance and high auto-gap. After the comparison of results from previous before and after study (3), Violation Type 4 (illegal entry, illegal exit) increased for short crossing (from 12.5% to 20.5%). But Violation Type 4 (illegal entry, illegal exit) for long crossing decreased (from 21.4% to 5.6%). Pedestrians adjusted their speed to be on Violation Type 2 (illegal entry) to avoid Violation Type 4 (illegal entry, illegal exit)