The Virginia Department of Transportation presented preliminary results of an analysis of putting in regional express lanes on a nearly 40-mile section of interstate from the western end of the Hampton Roads Bridge-Tunnel to northwest of the Bowers Hill interchange at Dock Landing Road.

Christopher Hall, VDOT Hampton Roads District Engineer, told a meeting of the Hampton Roads Transportation Planning Organization Thursday that the purpose of the analysis is to understand the potential impacts of increased capacity of putting in the express lanes — also known as HOT lanes.

The HOT lanes would allow lower occupancy vehicles to pay a toll, while those with the required number of passengers would be allowed to drive in those lanes at no cost.

Hall said the analysis will also help identify potential challenges by 2025, when VDOT expects a number of highway construction projects to have been completed, including work in the Bowers Hill interchange, the High Rise Bridge and HRBT expansions and the interchange work at I-64 and I-264 at the eastern edge of Norfolk and western edge of Virginia Beach. He said this would have most of the HOT lanes only at the water crossings, including at the High Rise Bridge.

Hall describes this as the baseline of the interstate network that will be in place in 2025.

VDOT favors a plan to separate traffic in the Bowers Hill interchange through barrier-separated lanes and braided ramps, or flyovers, at a cost of about $450 million and is taking comments in an online survey through Sunday. The Commonwealth Transportation Board is expected to approve a recommendation for the interchange sometime this summer. Meanwhile, the first phase of the High Rise Bridge expansion is expected to be complete by July 2021.

In what he refers to as Scenario 2, VDOT would extend the entrance to the HOT network, Hall said, farther west, away from the HRBT, and converting the high-occupancy vehicle lanes from the interchange at I-64 and I-264 to a managed HOT lane.

“The purpose really boils down to four points, and that is, to understand what are those potential impacts in the system … that we might see by the increased capacity coming through an expanded (HRBT) project,” Hall said, “and also coming from the expanded capacity through Bowers Hill and over the High Rise Bridge.”

The other three points include evaluating speeds and travel times through the area of the interstate being looked at in the analysis, providing performance comparisons between the status quo — what is in place through improvements coming from construction projects that will be finished by 2025 — and providing HRTPO with the best information possible to make an informed decision on next steps.

Its study found five main choke points of congestion — most of them occurring eastbound during evening rush hour. He said with the HOT lanes in place, about 30 percent of total traffic volume would use those lanes at peak times, with travel time in the general traffic lanes expected to be cut by about seven minutes eastbound and four minutes westbound.

Hall said this is the first time VDOT has looked at the region and the I-64 network as a continuous network.