The art of easing a city's traffic gridlock
Congestion pricing strategies are surfacing around the country to address traffic flow and boost infrastructure funds.
As urban populations increase and new commuter services become available nationwide, cities are increasingly dealing with the scourge of transportation: traffic.
To combat traffic in the Big Apple, a Fix NYC advisory panel recently unveiled a congestion pricing plan for lower Manhattan, which has been met with heated debates and protests. The plan comes on the heels of a similar move in the Washington, DC suburbs of Northern Virginia, where many solo motorists took a hit to the wallet when congestion pricing kicked in on I-66.
Different cities employ various tactics for operating congestion toll systems, but the end result is the same: Motorists pay more to drive in certain areas during peak times when the roads are most clogged with vehicles, such as morning and evening rush hours.
One main framework — which will be used in New York — involves charging a flat toll during peak times; in some areas the toll is simply higher than at off-peak times, and in other areas no tolls are collected at all during off-peak times. The other main congestion pricing tactic is to incorporate variable pricing, in which technology is installed on roadway infrastructure to provide real-time traffic feedback and automatically raise tolls during periods of high congestion.
Although free high-occupancy vehicle (HOV) lanes used to be viewed as the answer to ease traffic gridlock, "congestion, particularly on the urban highways, has gotten to the point where it’s extremely difficult to manage," even with HOV lanes, said Ken Philmus, senior director of global business development and transportation at Conduent. Now, transportation agencies are beginning to "take a look at those HOV lanes or other lanes that they have the ability to widen, and [converting them] to ‘managed lanes’ or ‘express lanes’ or ‘high-occupancy toll lanes.'"
The variable pricing toll systems measure traffic levels with "intelligent transportation systems ... either by loops in the roadway or video cameras that can determine the congestion," Philmus said.
In Minneapolis, which uses dynamic pricing in its toll lanes during peak times, loop detectors are installed in the roadway every half mile to "monitor the traffic in the [MnPASS] lane ... [The system] raises or lowers the price every three minutes depending on how much traffic is in that lane," said Bobbie Dahlke, MnPASS and congestion management communications coordinator for the Minnesota Department of Transportation.
"If we had it at 25 cents all the time, there would be tons and tons of people and ... it would become gridlock, just like the other general purpose lanes," she explained.
Generally, the goal is to keep traffic flowing at 45 mph or faster during peak times. The dynamic pricing can occur either in protected lanes that are separate from general use lanes, such as the I-95 express lanes in Miami, or on all lanes of a roadway, such as on I-66 during rush hour in Northern Virginia. Dynamic signage near entrance ramps displays real-time toll prices for single-passenger vehicles; as is the case in Northern Virginia and Minnesota, high-occupancy vehicles often are exempt from the variable tolls.
Some drivers were in an uproar over the start of dynamic tolling in Northern Virginia last month, due to single-driver vehicles racking up tolls of up to $40. Experts say the system worked exactly as it was supposed to and that high-occupancy vehicles weren’t subject to tolls, only solo motorists using the road at peak times.
"There is no randomness to the pricing ... I-66 started at an incredibly high toll rate because so many [solo drivers] wanted to use it ... The pricing had to be so high to keep the travel at 45 mph," Philmus said. "We really find that the public responds to the pricing" and alters their commutes during peak times, which decreases congestion.
"There is no such thing as a free road. Somebody’s got to pay for it somewhere, somehow."
Conduent, senior director, global business development, transportation
The Florida Department of Transportation (FDOT) found so much success in reducing traffic congestion by eliminating standard HOV lanes and adding express lanes on I-95 in Miami-Dade County that it not only expanded the practice throughout South Florida, it also moved forward with plans for dynamic tolling in urban areas throughout the state — Orlando, Jacksonville and Tampa.
FDOT launched dynamic pricing in Miami in 2008, and five years later data showed that the express lanes had drastically improved peak time traffic flow. Before the system was put in place, morning commute speeds were 20 mph in HOV lanes and 15 mph in general purpose lanes, but by 2013 that leaped to 62 mph and 56 mph, respectively. Evening commute speeds experienced similar changes. "All the lanes had a very substantial increase in operating speed, including the ones that weren’t tolled," said FDOT District 6 Secretary James Wolfe.
Although Minnesota touts the MnPASS system as being solely for congestion reduction and "not a strategy to generate revenue," other transportation agencies overtly state that the tolls collected through congestion pricing go directly toward funding transportation infrastructure. New York, for example, reportedly will use funds gathered through congestion pricing tolls for subway system improvements. A number of agencies consider the funding crucial to update aging transportation infrastructure, especially during an economic climate with tight state and municipal budgets and funding uncertainty at the federal level.
"There is no such thing as a free road. Somebody’s got to pay for it somewhere, somehow," Philmus said. He explained the increasing realization of this fact is prompting more transportation agencies to add toll roads, and especially variable price tolling. It brings transportation more in line with "almost every other commodity — like power and water and things like that — where the pricing is based on usage."
Obstacles and enforcement
A tricky aspect of implementing a dynamic pricing toll system is deterring toll skipping. The Florida Highway Patrol helps FDOT with enforcement, which is "very important for people to use the lanes properly,” according to Wolfe.
One problem that FDOT has encountered since installing express lanes is "lane diving," in which motorists in the toll lanes run over the flexible plastic barriers to quickly move to the general use lanes in an attempt to avoid getting picked up by sensors. To combat that problem, FDOT last year installed sturdier poles, doubled the number of them and placed them at 5-foot intervals instead of 10-foot intervals. Those changes led to an 89% reduction in ticketing, and a 30% reduction of crashes in the express lanes.
"You can tinker with design and tinker with enforcement and ... redesign the operations to make them more efficient and effective," said Wolfe.
Some of that tinkering is necessary to anticipate tolling solutions for emerging mobility options, such as connected and autonomous vehicles, or even ride-sharing. New York, for example, included for-hire vehicles in its congestion pricing plan, instead of considering them high-occupancy vehicles. "I don’t think we really know yet exactly how that’s going to affect congestion," Philmus said.
Still, he anticipates that interest in congestion pricing strategies will only continue to grow. "We’re going to see a lot more of this," he said, noting that agencies at both local and state levels are looking at it as a tactic to improve traffic flow and boost infrastructure funds.
"We've analyzed the safety, the operations, how much traffic we’re moving [and] what the operating speeds are," Wolfe said. "I’m personally very excited about the success of express lanes. They really do work."
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