In a nutshell, this site presents a dozen collision patterns I’ve seen in my work as a traffic engineer that tend to occur at high collision locations on city streets. It includes two more urban street patterns that don’t tend to occur at high collision locations, but of which drivers should also be aware. These are real world conditions that drivers will likely encounter on city streets. These situations present levels of complexity by which drivers are challenged and often make mistakes. The result is that, too often, collisions occur and, too often, people get hurt.

In my experience as a traffic engineer, I hadn’t seen this kind of information collected and
presented in one place. My aim in creating this site is to share this information to improve safety for street users, including drivers, pedestrians, and cyclists. This can be used to help:

Engineers, planners, and street designers design safer streets.

Drivers—particularly new and learning drivers—be aware of and recognize these patterns. To do this, this site describes what they “look like”—including the kind of streets they generally occur on, the traffic conditions when they take place, and the movements street users are trying to make.

Safety research. One way this information could be of use is in helping to recognize different fundamental factors that contribute to the different types of collisions—that this might affect the aggregation/disaggregation of collision data used in traffic safety studies. This could affect, as well, how street safety studies that use fully aggregated collision data are interpreted.

A point of emphasis in the presentation of this information is that walking and bicycling are intrinsic parts of healthy urban street systems. As the smallest users (in terms of physical size) of the street, pedestrians, bike riders, and motorcyclists require special consideration in terms of safety. Their small size and mass translates to being vulnerable to the force of collisions. A large proportion of collisions on city streets that end in severe injury and as fatalities involve pedestrians, bicyclists, and motorcyclists. This site presents information about urban collision patterns involving pedestrians and bicyclists so everyone can be on the lookout for these patterns.

The high-collision location types presented, while common to many cities and urban settings, are limited by my own experience. No doubt, others (including traffic engineers, street users, and driving instructors) in other cities have observed other high-collision patterns and patterns that too often result in serious outcomes. My hope is this work suggests a platform to which these patterns (presented in similar detail) can be added—so that street users may benefit from awareness and understanding of these patterns, as well.

Mike Morris-Lent
Morris-Lent Engineering LLC