Metro Neighborhood Traffic Management Program (MNTMP) Manual - Techniques and Strategies
Table of Contents
MNTMP TECHNIQUES AND STRATEGIES
Metro Public Works recognizes that the true root cause of residential traffic management complaints is an over-stressed or under-utilized arterial/collector system known as a thoroughfare system. The most effective way to eliminate an issue is to remove the root cause. A long-term goal of MPW is to improve the major roadways. This includes improvements within neighborhoods.
Metro Public Works has examined many different neighborhood traffic management techniques in use today. Realizing that Nashville neighborhoods are not all the same and have a variety of different street designs, the MNTMP program includes a wide range of techniques that may be used to address unique street and traffic conditions on local residential streets.
Traffic management techniques generally fall under two categories - physical and psychological. In general, low volume wide roads encourage higher automobile speeds. Consequently, many traffic management techniques are designed to physically change the width or alignment of the street. Techniques such as striping patterns, neckdowns, roundabouts and medians can decrease road width.
If a motorist can see far into the distance, their speed generally increases. Sight lines can be interrupted or decreased by using techniques such as slow-points, roundabouts, and changing surface pavement to break the road into smaller visual units. These techniques may cause drivers to slow down. These techniques also encourage motorists to widen their field of vision, thus becoming much more aware of pedestrians and bicyclists. Proper changes in road design encourage traffic to travel at a slower, more even pace.
Traffic management may also be achieved by changing the psychological feel of the roadway. Streets using different surface types, vertical landscaping or narrowed lanes create the appropriate space for a relaxed, pedestrian-friendly feel. These psychological changes give motorists cues that they are no longer on a major roadway but are in a residential environment and they must share the roadway with other users.
All traffic management techniques have a limited range of effectiveness. To achieve their objectives, some techniques need to be placed every few hundred feet. If techniques are used too sparsely, traffic may slow upon reaching the installation, but the overall speed along the street will probably not decrease. One technique may be used multiple times or multiple techniques may be used in conjunction with one another. Some techniques can affect emergency service response, traffic noise, air quality, congestion, fuel consumption and many other factors. Some can have a positive effect on these conditions while others may have a negative one.
The intent of this program is not to solve internal residential conflicts. The role of Metro Public Works is to help mitigate the effects of speeding motorists caused by deficiencies in the city’s thoroughfare system. Metro Public Works will work with a neighborhood to offer techniques and strategies to help it solve its own internal issues.
Emergency vehicle access and response time will be carefully considered when designing and installing traffic management devices. Studies have shown that some devices may slow response times up to ten (10) seconds per device. This impact must be understood and considered by neighborhood residents when developing their traffic management program.
Likewise, bicyclists, pedestrians and other street users must be considered when developing a traffic management strategy because some devices can obstruct their movements. Many devices can be modified to allow bicyclists and pedestrians to bypass them. For instance, a diverter can be fitted with a bicycle/pedestrian path to allow for those users’ particular access needs.
Options for neighborhood traffic management techniques have been structured into stages. The first stage is the least restrictive and typically has the lowest cost, while other stages are more restrictive and costly, and may require approvals beyond the process outlined in the MNTMP. These options have been chosen for their impact on vehicle speeds and volumes on residential streets.
Neighborhoods benefit most when traffic management techniques are incorporated into a neighborhood traffic management program. The focus of this program is to address the overall neighborhood concerns. Although a change may occur on only a single street, MPW will review how the change has impacted the rest of the neighborhood. In most cases multiple streets will be involved utilizing a variety of different traffic management techniques to find the best approach to address the entire neighborhoods concerns.
Because residents are the main initiators and beneficiaries of traffic management, it is critical that they be as much a part of the process as possible. Developing a program early on that addresses neighborhood traffic safety and livability concerns on an area-wide basis encourages citizens to become actively involved in the improvement process. In this way, Metro Public Works and residents can work together to create safer and more livable neighborhoods throughout Nashville.