I-95 south of Petersburg, Virginia. Image by Taber Andrew Bain licensed under Creative Commons.

If you want to ease congestion and improve travel times on Interstate 95, widening the roads won’t do the trick.

That’s a conclusion reached by the Virginia Department of Transportation after studying how to improve the busy I-95 corridor throughout the state. Sections in Northern Virginia are some of the busiest and most congested spots in the country, by some measures, and VDOT predicts that adding one to three general-purpose lanes to I-95 would bring “minor to no speed improvements” by 2040.

Researchers reached that conclusion in part by looking at what the state has tried already. As one example, VDOT added a fourth general-purpose lane to I-95 in 2011 and found that it didn’t reduce travel times long-term—in fact, speeds since then have gone down, which means worse congestion instead of relief.

“Additional general purpose lanes do not address these goals [to improve travel time reliability] on the I-95 corridor,” VDOT said in an October presentation about its I-95 improvement plan. “Transit and carpooling offer best opportunities.”

This recently widened section of 95 has only gotten slower since the new lane opened. Image by VDOT.

Part of the reason adding more roads may be ineffective is because more people are choosing different ways to get around on the corridor.

The decline of the single-occupant vehicle

Today most people traveling through the corridor aren’t driving by themselves. They’re using a mix of transit and carpools, in some areas making up about 60% of the travelers along the I-95 corridor at rush hour.

That’s important because it means that solutions aimed at moving more and more cars may not be helping the greatest amount of people traveling through the area. Another important thing is that transit and other driving alternatives can move a lot of people even in places that do not seem particularly transit-friendly.

And that shows up in other places as well. In an online survey, VDOT asked participants what improvements people wanted to see in the corridor. The two most popular responses were improved and expanded Metro and Commuter Rail service.

That bodes well for the state’s recently announced plans to greatly expand VRE service thanks to a series of plans throughout the corridor aimed at increasing commuter rail frequency through the state.

The people want transit! Image by VDOT.

That said, some pure road improvements are planned. There are plans to expand the I-95 express lanes where speeds are kept constant through tolling down across the Rappahannock River into Fredericksburg. Smaller plans to extend acceleration and deceleration lanes are in the works for a number of exits where there are persistent back ups.

Another big project is improvements to real-time traffic adjustments on nearby roads like US-1 which is a local alternative to I-95 that often faces punishing back-ups that block parts of the road, when there are crashes.

A real-time system that could change traffic light timings could improve traffic throughput when those crashes occur.

Doubling the number of lanes on 95 wouldn't do much to make traffic better.  Image by VDOT licensed under Creative Commons.

Beefing up bike and pedestrian infrastructure

A gap in the study is a lack of options when it comes to walking and biking. That’s not an option on I-95 itself, but identifying ways to make local trips easier to make by walking and biking can reduce pressure to take cars instead. Additionally, Virginia does have a number of trails along the East Coast Greenway aimed at providing cycling and walking routes across the state and entire east coast.

Notably, while the study is focused on the I-95 corridor, it’s looking at more than just cars on that road. Officials were tasked to look at how many people were traveling through the corridor, rather than just how many cars and trucks moved through the area.

The push for a people-orientated study was due to the efforts of State Senator Scott Surovell, who represents some of the areas inside the corridor in Northern Virginia.

While the idea that there is no easy “fix” to congestion on I-95 might be discouraging to some, it’s also an encouraging sign from VDOT to see the emphasis on expanded transit and alternative options when it comes to traveling throughout the state. That’s good for Virginians, for traffic, and the environment.