Access Management is the process of managing access to land development while preserving capacity and improving safety. The basic principles of access management include:
Limiting The Number of Conflict Points
At intersections along roadways a variety of vehicle paths will cross, merge into or diverge from one another. Anyplace this happens a conflict point exists. Conflict points are good indicators of the potential for accidents. The more conflict points that occur at an intersection the higher the potential for vehicular crashes. A typical 4-leg intersection has 32 conflict points, however, when left turns and cross street through movements are restricted, the number of conflict points drops to 4. Thus the potential for crashes is significantly reduced.
Separating Basic Conflict Areas
Intersections of public streets as well as intersections of public streets and driveways represent basic conflict areas. High levels of activity can occur at these locations and, consequently, through traffic needs time to react to the decelerations, accelerations and travel paths of other vehicles at or near the intersections. Adequate spacing between intersections allows drivers to react to one intersection at a time and provides greater opportunities to avoid potential conflicts at each successive downstream intersection.
Reducing Interference with Through Traffic
Traffic often needs to slow down for vehicles exiting, entering, or turning across the roadway. Providing turning lanes and restricting turning movements allows turning traffic to get out of the way of following through traffic.
Providing Adequate On-Site Circulation and Storage
The design of good internal vehicle circulation in parking areas and on local streets reduces the number of driveways that businesses need for access to the major roadway.
Access Management is crucial to the successful longevity and functionality of any traffic system. The Federal Highway Administration has concluded the following benefits of access management;
- Access management provides substantial reduction in accident costs
(AASHTO indicates that 50% to 70% of all accidents are access related) - Access management maintains the efficient movement of people and goods
- Access management preserves the public investment in transportation infrastructure
- Access management reduces the need to build more roadways
- Access management protects the value of private investment
- Access management enhances the environment and economy of communities