Localized Bottleneck Reduction
USDOT Congestion Initiative Focus
Operational Solutions to Bottleneck Congestion
Each time we get in our cars we increasingly plan for delays we "expect" to encounter. For example, if its rush hour we know we can expect to sit in bumper to bumper traffic. Further, we can confidently predict just where along our route we can expect to be sitting. The experience of expecting where and for how long we will be delayed can be attributed to recurring congestion, as opposed to nonrecurring congestion, i.e., random events due to traffic incidents, bad weather, work zones, and special events.
An image of vehicles in multiple lanes of congestion.
Bottlenecks are hallmark signatures of congestion. Recurring congestion, specifically, "inadequate physical capacity" (a.k.a., bottlenecks) accounts for 40 percent of on-the-road congestion. Think of a clogged storm pipe. The clog, or bottleneck, is identifiable, point-specific, and ultimately, treatable. Absent the clog, the pipe flows freely and sufficiently for its size. However, if a larger sized pipe is needed in the first place, that is akin to an overarching congestion problem, one that is remedied by either reducing the demand on the pipe, or upsizing the pipe. Engineers are increasingly seeking to remove the "clog" first, or reduce the demand, before conceding to replace the whole pipe. Given that the term "bottleneck" can be either a recurring or nonrecurring event, the Localized Bottleneck Reduction (LBR) Program addresses the former type.
Major reconstruction projects are often justified as the only valid solutions to fully relieve congestion at the worst bottleneck locations. However, the cost of executing such projects is usually enormous. They can take many years to complete, or many years to even schedule due to budget limitations. This is why relatively low-cost geometric and operational improvements (e.g., auxiliary, shoulder, narrow, high-occupancy vehicle, reversible and contra flow lane designs, and ramp metering) should be considered to mitigate the effects of a local bottleneck, even if only in the short term until a more major project can be implemented.
The USDOT recently introduced the Localized Bottleneck Reduction program. This program focuses on quick-to-implement, point specific operational or low-cost construction fixes to address recurring choke points. The goal of the LBR program is to facilitate the sharing of such applications and to demonstrate their value.