Engineering

Teen Driver

Traffic Calming

The term "traffic calming" is often applied to any physical changes to the roadway intended to reduce speeds or promote safety for pedestrians and other nonmotorized road users. However, traffic calming can also include a variety of strategies for educating drivers and making people aware of unsafe driving behavior.

Traffic calming solutions must be tailored to the situation in order to be effective. Matching engineering changes with appropriate public education and enforcement efforts will make a traffic calming project much more likely to succeed.

Traffic calming is often associated with context sensitive design – a set of principles that helps engineers reach the most appropriate design decision for a specific location or set of circumstances.

Rural Road Safety Solutions

Minnesota's Local Road Research Board (LRRB) and MnDOT's Division of State Aid for Local Transportation developed Rural Road Safety Solutions for local agencies. A key message of the training was about the safety "revolution" afoot in Minnesota, whereby those responsible for roadways are asked to focus on low-cost prevention strategies that address traffic fatalities and serious injuries, rather than simply looking at overall crash rates.

Eight workshops were presented throughout the state by a team that included the FHWA safety engineer for Minnesota, the MnDOT state traffic safety engineer, three county engineers, and the consultant who developed the curricula. Attendees left with an understanding of the many tools and technologies available for the assessment and improvement of rural roads. The workshops also provided information about highway safety trends at the national, state, and local levels; specific engineering strategies to improve safety; and funding and how to garner support for safety-related projects.

Local and State Traffic Engineers

Building a relationship with your county or city engineering staff is the most important step in resolving questions about engineering and roadway safety. Ensuring safety is one of the primary responsibilities of public works engineers, and their training gives them the tools to evaluate safety issues and recommend effective solutions.

In addition to county and city engineers, your Minnesota Department of Transportation (MnDOT) district office is also an excellent resource. MnDOT works with county and city engineers on many road construction projects and oversees large projects on major state and federal highways (see Road Safety Audit, below).

Examples of Engineering Efforts

Engineering changes to improve safety and mobility can range from simple road striping improvements to the complete reconstruction of entire highway corridors. Some examples include:

  • Improving intersection signs
  • Upgrading pavement markings for better visibility in all weather conditions
  • Installing street lights at intersections
  • Changing the vertical alignment (grade) of intersections
  • Upgrading guard rails to accommodate higher vehicle speeds
  • Cable median barriers
  • Rumble strips/stripes

Road Safety Audit

The Minnesota Departments of Transportation and Public Safety have developed a road safety audit (RSA) procedure to evaluate safety issues on major road corridors. The goal of an RSA is to reduce crashes using methods that can be implemented quickly, in accordance with overall plans for a traffic corridor.

An RSA is carried out by a multi-disciplinary team of engineers and public safety specialists who meet with community representatives and local engineering staff before starting their investigation.

Following is an excerpt from a road safety audit of Highway 52 in Minnesota:

"Based on a review of crash data and a field review of the corridor, it appears that the biggest issues contributing to crashes are minor street crossing maneuvers combined with the lack of gaps in the traffic stream on Highway 52 and high vehicle speeds (especially during adverse weather conditions). However, multiple causes of crashes were noted – suggesting that a coordinated Engineering/ Enforcement/Education/Emergency Services approach is required to address safety along Highway 52."

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