Current RTA focus
RTA supports the ongoing effort to review the potential of implementing express shoulder lanes on I-540 as a lower cost, lower impact, faster implementation congestion relief option for our region.
RTA also supports the ongoing feasibility studies by NCDOT of possible permanent express lanes for portions of I-40, I-440, I-495, I-540, and NC 147 in the Triangle region, including the scaled implementation of same.
RTA looks forward to learning from managed lane efforts elsewhere in North Carolina and in other areas.
Overview of express lanes and express shoulder lanes
Most freeway lanes are open to all vehicles, trucks, buses, etc. at any time. Under high usage conditions it becomes challenging or impossible to provide reliable travel as demand approaches or outstrips capacity.
One option is to create new freeway lanes and then “manage” (i.e., reserve or restrict entry to) just the new lanes. “Express Lanes” are a specific type of managed or restricted lane that requires electronic payment of a variable toll to enter and use the lane. By varying the price by time of day, this can harmonize demand and capacity, encourage off-peak usage, ensure reliable trip times and maximize the efficiency of the freeway express lanes.
One might think of “Express Lanes” as the personal travel equivalent of USPS “Express Mail” – paying for faster, more reliable travel for ourselves. Optimizing the flow on the express lanes will also maximize the relief to the “general purpose” (untolled) existing freeway lanes.
The Triangle region has no express lanes or other managed lanes, other than our part-time Bus On Shoulder System (BOSS) operational treatment on portions of I-40 and Wade Avenue Extension freeways. However, portions of several freeways in the Triangle region are under feasibility study for Express Lanes, and NCDOT is examining the potential of implementing express shoulder lanes on I-540 as an accelerated congestion relief solution.
RTA policy on Express Lanes and Express Shoulder Lanes
RTA supports an “Express Lane”, variable toll approach — the method used on the I-95 Express Lanes north of Baltimore, Maryland — for added, managed freeway lane capacity. We support the consideration of adding new freeway lanes as express lanes, rather than general purpose lanes, when a freeway already has three or more through travel lanes per direction.
An express lane framework has several benefits:
- Creates a reliable, on-demand option to avoid congestion
- Variable pricing of all vehicles maximizes operational flexibility, with zero toll possible during times with low congestion
- Eliminates the need to enforce vehicle occupancy
- Pricing encourages carpooling and vanpooling above typical 2-person high occupancy vehicle (HOV) threshold used in most other regions
- Creates an express route for buses without building separate busways or relying entirely on BOSS operation
- Toll revenue can be used to accelerate construction of lanes
- Minimizes individual toll rates, since all vehicles using the lane pay for usage
Examples of “Express Shoulder Lanes”
“Express Shoulder Lanes” are currently used on eastbound I-70 in Colorado west of Denver and I-35W in Minneapolis — as a lower cost, faster implementation, higher utilization managed lane treatment. Like the Triangle’s Bus On Shoulder System (BOSS), possible Express Shoulder Lanes would operate on a part-time basis — only under congested conditions.
Watch this video of I-70 Mountain Express shoulder lanes in Colorado:
An express shoulder lane framework has several additional benefits:
- Smaller footprint means reduced right-of-way requirements and lower cost of construction
- Reduced cost can improve likelihood of funding and accelerate the project
- Lower project costs mean reduced toll rates, and allows the variable toll to focus more on managing demand and ensuring free flow and less on repaying construction bonds
- Lower toll levels mean higher utilization of peak shoulder lanes and therefore more relief for travelers in general purpose lanes
- When there is no congestion on the general purpose lanes – which is the case the vast majority of the day – there is no need for express shoulder lane operation, and the lane acts as a normal shoulder
Recent successes of RTA and partners
- I-40 in southern Wake and western Johnston County currently undergoing environmental analysis for possible future permanent express lane construction
- RTA presented to Capital Area MPO about possible express lane concepts in region in 2013; CAMPO thanked NCDOT for studying express lane concepts on I-40
- RTA presented to Durham-Chapel Hill-Carrboro MPO about possible express lane concepts in region in 2012
- Portions of I-40, I-440, I-495, I-540, and NC 147 currently undergoing feasibility study for consideration of possible future permanent express lane construction
- The I-40 Regional Partnership, coordinated by the RTA business coalition, launched a express shoulder managed lanes action team in summer 2015, with a current focus on a potential implementation on I-540.
- The Capital Area MPO submitted an express shoulder lane project for I-540 in northern Wake County.
Notes on I-77
In April 2014 NCDOT announced plans to convert and expand existing high-occupancy vehicle (HOV) managed lanes on I-77 north of Charlotte to high-occupancy toll (HOT) lanes during the next few years, and those lanes are now under construction. While we are focused on new Express Lanes and express shoulder lanes rather than a HOV to HOT lane conversion for our region, we may still learn valuable lessons from Charlotte’s managed lane experience.