In the past, much, or all, of recurring congestion was felt to be a systemic problem ("not enough lanes") but much of the root cause of recurring congestion is in fact subordinate locations within a facility; i.e., "bottlenecks" and chokepoints. Elsewhere on the same facility and during the same hours, the facility runs free. This document is meant to discuss when, where and how to study small, localized sections of a facility (e.g., on/off ramps, merges, lane drops, intersections, weaves, etc.) In cost-effective means. Some chokepoints are (or seem) obvious in their solution; add a turn lane, widen a stretch of highway, retime a signal, or separate a movement by ramp. However, the solution can often lead to hidden or supplementary problems; hidden bottlenecks, disruptions upstream, or undue influence on abutting accesses, etc Analyzing localized sections of highway is different from analyzing entire corridors or regions. Micro simulation analysis products vary in their target applications and purported results. This document will provide guidance that specifies the choice of analysis tools and inputs necessary to analyze localized problem areas. It also provides some guidance as to when analysis it warranted, and what data inputs are required. (Author/publisher)
Abstract