When light rail trains intersect pedestrian crossings, their conflicts are typically controlled by traffic signals. However, when the setting of the two conflicting modes shifts to a college campus where most people walk or bike, the typical approach to light rail-pedestrian conflict management gets turned on its head. Can the two modes coexist peacefully? The answer is yes, with some careful planning.
Case Study: University of Maryland at College Park (UMD) and the Purple Line
The Purple Line is a 16-mile light rail system connecting the northern suburbs of Washington, DC and tying into several bus routes, Metro lines, and commuter rail lines. At the center of its path is the campus core of UMD: a 0.5-mile segment of the campus with 15 uncontrolled crosswalks and high pedestrian traffic. At these unsignalized crossings, the Purple Line train operators will be expected to yield right-of-way to pedestrians.
Naturally, the University had some concerns about the viability of this plan—could the rail system successfully coexist within a busy college campus without compromising the safety and convenience of all involved? These questions are relevant not only to UMD’s specific situation; they are being asked nationwide. This case therefore has a wider relevance to the transportation industry at large.
On college campuses like UMD, pedestrian activity at unsignalized crossings is often the source of auto congestion. Furthermore, that pedestrian activity typically has non-uniform flow rates with periodic spikes dependent on the class schedule. We therefore needed a flexible multi-modal traffic analysis tool that would allow us to accurately model the interactions between pedestrians and automobiles, buses and Purple Line trains, and record measures of effectiveness for all users. We ultimately selected VISSIM for this process, which is a powerful multi-modal micro-simulation software.
Using VISSIM, our team evaluated impacts to pedestrian delay and train travel times in 15-minute increments during the peak commuting periods. This allowed for a network-wide evaluation of how the trains would affect traffic and pedestrians when students were in class as well as during pedestrian surge activity between classes.
So, what strategies can we use to interweave heavy pedestrian traffic with light rail trains?
- Limit crosswalk consolidation. Every crossing on campus exists for a reason: people cross there. Therefore, consolidating even one would result in some level of inconvenience.
- Consolidate for safety issues. Crossing consolidation is essential for safety and must be done in areas without adequate train storage between two crosswalks. This will prevent trains from blocking crosswalks, which can induce risky pedestrian behaviors.
- Consider crossing volumes for train operations. Place crossings so that two adjacent, heavily utilized unsignalized crossings are not consolidated, because then the trains would never find a gap in pedestrian traffic.
As we learned at UMD, heavy pedestrian traffic and surface rail trains do not have to be mutually exclusive. With a lot of careful planning considering the needs of all involved, a light rail system can successfully traverse a busy college campus.