Jeff Stephenson, P.E., is the Team Leader of [...]
How can we improve travel times, reduce traffic crashes and congestion, preserve property values and preserve street capacity? Access management.
Defined as the planning, design and implementation of various land use and transportation strategies to maintain traffic flow and safety along a primary roadway, access management also considers access needs of various land uses and development types.
The key to effective access management is linking appropriate access design to roadway function. Appropriately spaced intersections along with minimal allowable driveways are basic elements commonly used as access management strategies.
By adopting standards for access management, agencies can streamline the decision-making process and maintain uniformity throughout their transportation system. Standards specify when, where and how to provide access.
Effective access management standards can promote intergovernmental cooperation relating to land development and transportation decisions that are cohesive throughout a region. Such efforts help adjacent property values while still preserving governing agencies’ financial investment in roads.
A primary goal of access management is to minimize the number of access points along a roadway facility.
Access management also minimizes the number of vehicle conflict points and directs turning vehicles to strategically identified locations.
Conflict points, or crossing interactions between vehicles, represent opportunities for delay due to congestion and crashes. Multiple conflict points increase a driver’s decision-making process. Drivers can only mentally process a single conflict point at a time. Designs with few traffic signals, non-traversable medians, channelized left turn lanes and “right-in/right-out” driveways are effective in promoting access management and minimizing conflict points.
Without applying appropriate access management techniques, a typical four-way intersection can have up to 32 total conflict points!
Sain is involved in several access management projects, which we’ll share more about next week.
Sain Associates, Inc., is headquartered in Birmingham, Alabama, with offices in Cullman, Alabama, Pulaski, Tennessee and Mandeville, Louisiana. Sain is a site engineering, traffic/transportation engineering and planning and land surveying firm with experience in more than thirty states.