Called “dynamic tolling,” the Colorado Department of Transportation claimed it will help to better manage demand during peak hours to maintain free flow traffic in express lanes.
The agency said dynamic tolling started earlier this year on the Central 70 express lanes, and it is scheduled for later this year for I-25 South Gap and the I-70 mountain corridor. It will eventually take effect on all express lanes in Colorado.
“Tolls on both the South Gap and Mountain Express Lane corridors will be similar to the time-of-day pricing drivers are accustomed to seeing on each corridor, ranging from $1.50 to $4.75 for South Gap and up to $9 on the Mountain Express Lane,” the agency said in a news release.
Officials insisted that the move would improve traffic flows, while some studies suggested it’s designed precisely to make the managed lanes more attractive, allowing operators to charge higher tolls.
According to the Colorado Transportation Investment Office, dynamic tolling is used to “improve traffic flow on congested highways by reducing delays on the most seriously congested corridors, creating reliable travel times, providing flexible and reliable mobility choices, and improving travel speeds in the non-tolled general-purpose lanes.”
The office is a state-owned enterprise, which means that it is not subject to Taxpayer’s Bill of Rights limitations on revenue or taxation. A board of directors, some of which are appointed by the governor, oversees the office, which cannot receive more than 10% of its total revenues from state or local governments.
Instead, it has the authority to issue revenue bonds and collect tolls from highway usage in amounts it determines and sets.
Studies on the utility of tolled lanes have been going on for decades, but dynamic tolling, which involves changing the toll amount very quickly, according to the office, has emerged as vehicle detection technology has improved.
The basic principle of toll lanes is that travel time can be reduced and travel speeds increased in both the toll and general-purpose lanes by making it more expensive than most people care to pay for the privilege of a faster trip; thus, keeping them in the free general-purpose lanes.
The primary difference between time-of-day (peak traffic) tolling and dynamic tolling is that the latter can make real-time adjustments to tolls based on traffic flows, and toll amounts can be determined by what are usually proprietary algorithms that best suit the objectives of the highway operators.
By how much speed increases and time decreases with either type of tolling is the subject of much research and debate, and is highly location dependent, but it seems to gravitate towards overall benefits of about 20%, according to studies. But the benefits are not evenly distributed among all drivers, and they favor toll lane drivers the most.
“The goal of this operational change is better traffic management,” Timothy Hoover, a spokesperson for CTIO, told The Denver Gazette. “We obviously have to charge a toll sufficient to cover the costs of paying back the money we borrowed to build an Express Lane and for operations and maintenance, but the primary goal of the toll is to manage demand.”
In its 2023 annual report to the Colorado General Assembly, the office suggested it intended to generate revenue for new transportation projects.
“CTIO has the legal responsibility to aggressively seek out opportunities for innovative and efficient means of financing and delivering important surface transportation infrastructure projects in the state. Among other benefits, it has the statutory power to impose tolls and other user fees, issue bonds, and enter into contracts with public and private entities to facilitate Public-Private Partnerships (P3s),” the office said.
Hoover pointed out that the US 36 Express Lanes corridor is the only one with a private operator.
The Federal Highway Administration said congestion tolls “pay for a different set of costs” that include the indirect costs of loss of productivity because some people are stuck in traffic, increased pollution from idling vehicles, and delays in delivery of goods.
“The delays that vehicles impose on one another on congested highways temporarily balance demand and supply but only by deterring travelers (and shipments) whose time may be more valuable, while wasting large amounts of others’ time,” said the federal’s agency FAQ on the subject.
“The idea behind congestion pricing is that each user should pay the external costs (i.e., the congestion) that their use of the road imposes on the network and other users,” said a 2021 research study called “Investigating the impacts of I-66 Inner Beltway dynamic tolling system” in the Journal of Transportation Engineering.
On Jan. 24, 2018, Washington’s Top News reported that on I-66 in Virginia, drivers using the toll lanes who began the nine-mile trip from the Beltway to Rosslyn or D.C. at 8:30 a.m. were charged $46.75.
Hoover told The Denver Gazette that tolls are determined based on traffic volumes and speeds only in the Express Lanes. Toll rates increase when traffic volumes increase and speeds decrease, and toll rates decrease when traffic volumes decrease, and speeds increase in express lanes.
But, said Hoover, all lanes benefit to some extent by the traffic using the managed toll lane.
“Prior to the start of dynamic tolling in 2024, from June through August of 2023, the percentage of time that corridor speeds dropped below 45 mph was an average of 1.31%,” Hoover said. “In 2024, during that same time period, the percentage was down to .31%.”
“Our data for Central 70, the first corridor to see dynamic tolling, shows that for speeds from January to October 2024, average speed in the peak hour was 45 mph for general purpose lanes and 59 mph for Express Lanes in both directions,” said Hoover. “The highest traffic peak occurred at 4 p.m.”
That’s a 14-mph speed differential. The Central 70 speed limit is 55 mph.
“Decreasing toll amounts at the right time incentivizes drivers to use the Express Lane. For example, if you are driving westbound on the I-70 Mountain Express Lane early on a Friday, traffic might not be quite heavy enough for you to consider paying the standard $9 toll, which is a time-of-day price,” Hoover said. “But, if the toll were just $6, which is the new lowest rate on the Mountain Express Lane, you might consider paying it.”
According to research, dynamic tolling also allows toll authorities to maximize revenues that it can use to achieve their statutory mandates.
A 2015 working paper from the Columbia University Center for Pricing and Revenue Management said maximizing operator revenues is achieved by “(raising) tolls prior to anticipated peaks in order to divert traffic to the unmanaged lanes and thereby increase congestion on those lanes and decrease congestion on the managed lanes — an approach we call jam-and-harvest.”
“These two effects combine to make the managed lanes more attractive to future drivers, enabling the controller to charge higher tolls than would have been otherwise possible,” said the paper, “Revenue Maximizing Dynamic Tolls for Managed Lanes: A Simulation Study.”
Studies of tolling, both time-of-day and dynamic tolling confirm there are speed and time improvements from having toll lanes. The question is how much of an improvement is there?
A 2021 study, called “Comparing Pricing Mechanisms for Managed Lanes” from the National Institute for Congestion Reduction at the University of South Florida, suggested there is little difference between the two tolling methods.
“Overall, both pricing measures were found to keep traffic flowing on (managed lanes), and neither pricing method was clearly superior,” the study said. “Dynamic pricing was found to perform slightly better in most metrics. However, both pricing mechanisms did work well to keep MLs flowing and thus are viable options for ML operators.”
© 2024 The Gazette (Colorado Springs, Colo.). Distributed by Tribune Content Agency, LLC.
