How Do Quick-Fix Bottleneck Solutions Factor Into the National Strategy to Reduce Congestion?
Major reconstruction projects are often required to fully relieve congestion at bottleneck locations. However, the cost of completing such projects is usually enormous and they can take many years to complete. Relatively low-cost geometric and operational improvements (e.g., auxiliary, shoulder, narrow, high-occupancy vehicle, reversible, and contraflow lane designs; and ramp metering) can be implemented to mitigate the effects of a bottleneck.
States such as Maryland have achieved improved system performance by introducing low-cost improvements as bottleneck locations. The Maryland State Highway Administration (SHA) has a dedicated program of about $5.0 million per year for the identification and implementation of low cost traffic congestion improvements at intersections. The program has been well-received by the public and local governments. Projects typically include "quicker fix" type projects that can be done quickly, such as, signal timing upgrades, and adding turn lanes and through lanes at intersections. The Maryland SHA has also has had considerable success with projects to improve freeway ramps and improve freeway merge areas that have reduced congestion bottlenecks at low cost. Other States have also been exploring such quick-fix improvements.
In 2006, the FHWA conducted a scan tour of Greece, Germany, Denmark, the Netherlands, and England for the purpose of examining their respective congestion management practices, policies, and strategies. Whereas, the majority of the focus was on system-wide congestion management practices, some of the knowledge shared was pertinent to quick-fix solutions for bottlenecks and chokepoints.
Implementing low-cost construction and operational strategies to relieve bottleneck congestion can bring relief to travelers by not only reducing recurring congestion but also mitigating the impact of nonrecurring traffic disrupting events at bottleneck locations. For example, consider an accident that blocks a single-lane of traffic. If only two lanes existed prior to the incident, the impact would be greater than if three lanes existed. Therefore, bottlenecks not only affect recurring congestion but nonrecurring congestion as well. The Flip side of this is that strategies to alleviate bottlenecks also will lessen the delay caused by nonrecurring events. Further, because travel time reliability is determined by nonrecurring events, improving bottlenecks also will lead to an improvement in travel time reliability.
Identifying Bottlenecks at the Planning Level The Maricopa Association of Governments (Phoenix, Arizona) and the Southeastern Michigan Council of Governments (Detroit, Michigan) are two metropolitan planning organizations that have integrated bottleneck identification and analysis into their planning processes. It is critical that this happens to ensure that both short- and long-term funding are available for bottleneck remediation. More information may be found at: |
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