Factors affecting traffic operations on seven-lane cross sections

Field studies were conducted to evaluate the effects of roadway and roadside development factors on traffic operations and safety on seven-lane cross sections in urban and suburban areas. Acceleration noise, a measure of the relative smoothness of a trip, was used to assess the impacts of factors on traffic operations. Acceleration noise was collected in each lane in both directions during four periods (A.M. Peak, Off-Peak, Noon and P.M. Peak) at nine sites throughout Texas. Each of the sites exhibited different roadway and roadside development characteristics. From the studies, it was found that the quality of flow on seven-lane cross sections was impacted by such roadway and roadside development factors as the density of driveways located on each side of the roadway, the average daily traffic carried by a roadway, and the average number of unsignalized intersection approaches along each side of the roadway. Generally, as the density of driveways and the amount of traffic carried on a roadway increased, the ability of the driver to maintain a trip with few changes in speed decreased.