Congress Avenue Regional Arterial Study: Collector - Distributor Lanes

The concept of a collector-distributor lane system, as part of a regional arterial street improvement program is introduced. Such a system can improve operational aspects of certain urban arterial streets by provision of a transitional space between through-traffic streams and entering-exiting streams. Facilities for which this concept is most applicable, are arterial streets along which development has occurred that is inconsistent with the arterial street primary function which, according to the 1990 AASHTO Policy, is through travel and major circulation movement. For the comprehensive regional arterial program, as well as, the collector-distributor system the acquisition of additional right-of-way is regarded as cost, and or, time prohibitive. A literature review indicates that the concept of collector-distributor roads is addressed only moderately. The idea of exclusive right-turn lanes along arterials is covered in some detail, and many reports recognize the applicability of a right-most lane to separate turning and slower moving vehicles from through traffic. However, it appears that the literature is lacking in any works that specifically address the use of the right-most lane of an arterial in the manner in which this study proposes. Issues that have potentially significant impacts on design and operation of urban arterials are described along with those that specifically pertain to the design and implementation of collector-distributor lanes. These include channelization, control of access, driveways, weaving areas, and friction between traffic streams. Finally, potential benefits that can be derived from converting an existing through-traffic lane into a collector-distributor lane are identified. Criteria for implementation of a collectordistributor lane are described and recommended design standards and procedures are presented.