• Image 01
  • Image 05
  • Image 04
  • Image 03
  • Image 02

Safety

Article

Successful great streets should produce transportation and land use solutions that are both safe and feasible, while at the same time balancing other community values. Above all else, the public values safety and expects that transportation agencies will only implement solutions that provide an acceptable level of safety. The geometric design for a thoroughfare should properly reflect safety for all modes of travel. It should do so within the context of a host of constraints and considerations, including the type of place, land use features (both existing and planned), roadside and community effects, and cost considerations. Consider the images below - where would you feel safer walking?

Sidewalk
Credit: CH2M HILL
No sidewalk
Credit: CH2M HILL

Safety is a broad term and can have a variety of meanings depending on the setting.

In the world of great street planning and design, two types of safety are often referred to: nominal safety and substantive safety.

  • Nominal safety is a thoroughfare's relative ability to comply with standards, warrants, guidelines,and sanctioned design procedures.
  • Substantive safety is the actual crash frequency and severity for a given thoroughfare for all modes of travel.

For great streets, we are most interested in the issue of substantive safety. A great street design element should not necessarily be deemed unsafe simply because it does not comply with a particular standard or guideline. While noncompliance can be an issue, a thoroughfare's substantive safety - its "track record" - is a more fundamental consideration and is based on actual performance at a specific location.

When we talk about substantive safety for great streets, we are talking primarily about the crash risk that exists for all modes of travel: vehicular, pedestrian, bicycle, and transit. Great streets must provide environments in which all of these users can operate safely, without risk (or fear) of being involved in a crash. There are two very important great street characteristics to point out in this regard:

  1. High pedestrian presence is a hallmark of most great streets. In order to encourage such presence, the place must provide a safe environment for these users.
  2. Vehicular travel speed must reflect the desire for pedestrian safety. There is a direct correlation between high speeds and pedestrian safety. As speeds increase, crashes involving pedestrians are more severe.

Safe travel for all modes is a key objective in the St. Louis region. The East-West Gateway Council of Governments, the State of Missouri, the State of Illinois, and a number of other agencies are increasingly recognizing the importance of safe travel. In 2004, East-West Gateway spearheaded a major initiative under the banner “Someone’s Future is in Your Hands: Travel Safe.” The campaign is a component of regional and national efforts to reduce the number of driver and pedestrian traffic deaths.

Specific Points for Mixed Use Districts:

When planning for safety in mixed use districts, it is important to remember that these places typically have:

  • Significant pedestrian presence
  • Higher transit user and vehicle presence
  • Lower vehicle travel speeds

East-West Gateway has identified pedestrian safety as a critical component of the region’s travel safety initiative, based in part on the following considerations:

Vehicle speed vs. pedestrian survival
Credit: CH2M HILL
  1. Nearly 40 fatal crashes and a multitude of non-fatal but injury-inducing crashes involving pedestrians are reported in the eight-county St. Louis region each year. A significant portion of these crashes may have been preventable. As illustrated in the graph at right, vehicle travel speed also significantly influences pedestrian safety.
  2. Children, persons with disabilities, and older adults are the population segments at greatest risk for crash-related death or injury as pedestrians. These groups, namely older adults, also represent some of the nation’s fastest-growing population segments.
  3. The nation’s most desirable, livable communities are overwhelmingly pedestrian-friendly places. Downtown loft districts, mixed use developments, revitalized city centers, and new urbanist communities all require provisions for safe pedestrian travel in order to function successfully.
  4. Pedestrian safety can be considered an environmental justice issue. Older communities with pedestrian safety hazards such as deteriorating local streets, intersections, sidewalks, lighting, and signage are often areas with higher concentrations of minority and low-income households.
  5. Several regional, state, and federal plans and strategies support East-West Gateway’s goal of improved pedestrian safety, including Legacy 2030, the St. Louis Regional Bicycling and Walking Pedestrian Plan, Access to Independence, the Missouri Blueprint for Safer Roadways, and the Transportation Equity Act for the 21st Century (TEA-21).

In response to the above points, East-West Gateway has identified six key objectives for improving pedestrian travel safety in the St. Louis region. Five of these objectives are based on the National Cooperative Highway Research Program Report 500 series – Volume 10: A Guide for Reducing Collisions Involving Pedestrians. The six objectives are as follows:

  1. Reduce the speed of motor vehicles in areas where pedestrians travel
  2. Improve sight distance and visibility for motor vehicles and pedestrians
  3. Reduce pedestrian exposure to vehicular traffic (the fewer vehicle miles traveled, the safer the environment for pedestrians)
  4. Improve pedestrian access and mobility
  5. Improve pedestrian and motorist safety, awareness, and behavior
  6. Improve safety features on automobiles to minimize injuries in pedestrian crashes

As discussed in the Design Speed section of this guide, lower vehicle travel speeds are desirable in areas with a significant pedestrian presence. While reducing travel speeds can be challenging, especially in retrofit situations, design tools and planning methods such as traffic calming, enforcement, and appropriate geometric design and signing can help achieve this objective.

Significant transit use along a corridor has considerable implications for pedestrian travel patterns. Pedestrians in these areas may be more likely to cross the street to reach a destination, catch a bus, or transfer between modes. Adequate pedestrian facilities and treatments, such as mid-block and intersection crosswalks, pedestrian signals, instructional or informative signage, and pedestrian over- or underpasses are critical both for pedestrian safety and transit viability. It is also important to focus enforcement efforts on vehicular and pedestrian violations.

Low-profile barrier
Credit: CH2M HILL

The safety and appropriateness of planting street trees in medians or along the side of the road is a highly debated point among transportation researchers and practitioners. While street trees are often considered a desirable addition to the streetscape, some agencies are uncomfortable allowing trees to be planted in the clear zone.

According to research by AASHTO and other transportation organizations, some curb types may not be effective in preventing vehicles from crossing over the curb and striking trees at speeds above 30 mph. However, special low-profile barriers can be used to eliminate the potential safety hazard created by planting street trees along corridors with travel speeds in excess of 30 mph. As with any design choice, however, there are a number of tradeoffs which must be balanced.