Roads alone aren’t the answer to future congestion

One of the more important data sets to have been released recently are the new 2030 and 2040 population projections from the University of Virginia’s Weldon Cooper Center’s Demographics Research Group.

The Weldon Cooper Center is the commonwealth’s official demographer and their projections impact a whole host of state and local issues from school funding to our transportation studies.

The center projects that the commonwealth’s population will grow by another 813,981 people by 2030 and add more than 1.3 million by 2040 to bring our state’s entire population to nearly 9.9 million. Most of the media coverage pertaining to the Weldon Cooper Center’s data has been focused on the population aspects of the projections — such as if a locality is growing, shrinking, or aging — and a couple have focused on the political impacts of the data (here and here). 

I wanted to get into the potential transportation impacts of their projections.

One of the first things that really stood out was the massive growth along the Urban Crescent (DC-RVA-Hampton Roads), especially Northern Virginia (which I define as the counties of Arlington, Fairfax, Loudoun, Prince William, Stafford, and Spotsylvania; and the cities of Alexandria, Falls Church, Fairfax, Fredericksburg, Manassas, and Manassas Park). The Weldon Cooper Center is projecting NoVA to gain nearly three out of every five future residents by adding 476,000 residents by 2030 and 831,000 by 2040. 

The rest of the Urban Crescent (Greater Richmond down to Hampton Roads) will add another 25 percent of the state’s future residents: 214,000 by 2030 and 337,000 by 2040. Nearly 10 percent of the population growth will happen along the US-29/I-81 corridor from Fauquier County down to Lynchburg and over to Roanoke and the New River Valley. 

So, what does this mean for our transportation network? 

Well, the short answer is that traffic in Northern Virginia and along the Urban Crescent is going to get worse. And, attempting to fix the issue by building massive numbers of roads will drain every available transportation dollar from every corner of the commonwealth.

Here’s why I think that. Let’s make a couple of basic assumptions using the Federal Highway Administration’s Highway Statistics report. My first assumption is that the number of licensed drivers per citizen stays flat at 70 licensed drivers per 100 Virginians. My second assumption is that annual vehicle miles traveled (VMT) — the official measurement of how much we’re driving — per licensed driver also stays flat at about 14,400. My third and final assumption is that there will continue to be 89 registered vehicles per 100 citizens.   

If you extrapolate those assumptions out, then I estimate that we’ll add 569,000 more licensed drivers and 724,000 more registered vehicles by 2030. Those drivers will increase vehicle miles traveled on our road network by 8.2 billion over the course of the next decade. By 2040, we’ll have added 951,000 more drivers, 1.2 million more vehicles, and 13.7 billion more VMTs. What that means is, everything staying the same, traffic on our roadways will increase by more than 10 percent by 2030 and 16 percent by 2040. 

This is not unexpected, nor is it unrealistic. From 1990 to 2010, VMTs on our roadways grew 36 percent, and we added more than 1.2 million registered vehicles and 860,000 licensed drivers.

To get an idea of how much Virginians drive, I am using the Federal Highway Administration latest numbers which says that each of our 163,648 lane miles of roadways handle an average of about 521,000 VMTs annually.

As Virginia’s population has grown, so has our VMTs per lane mile: from 415,746 VMTs per lane mile in 1990 to what it is today. Most of that growth is from increased driving and a growing population, but other factors do play a part including expanded ridesharing and e-commerce deliveries.

However, if we wanted to draw a line in the sand and say we’re not going to let traffic get any worse, what would it take to preserve our current conditions?

There are handful of ways to accomplish that goal. Build copious miles of new roadways; do an all-the-above solution by investing in more rail, transit and bike/ped infrastructure; or something in between.

If we wanted to go the 100 percent roads route, then we would have to build 876 lane miles of interstate and a bit more than 25,500 non-interstate lane miles. Using an estimate of $2 million per non-interstate lane mile and $33 million per interstate lane mile, we would need to spend at-least of $80 billion by 2040 to maintain today’s traffic levels. That equals out to about a $1 billion more a year than the average road spending included in the commonwealth’s current six-year improvement plan.

However, there is an opportunity for a multi-modal solution. According to the U.S. Census Bureau’s latest American Community Survey, the vast majority (77%) of Virginians commute to work alone. Only 9 percent of commuters carpool, 4 percent use public transportation, 2.4 percent walk, and 1.7 percent use other means including biking. By investing in the other modes of transportation, they could be positioned to gain market share. 

Annually, each Virginia Amtrak regional train takes about 30 million passenger miles off our roadways and every Virginia Railway Express commuter rail train equals 4.2 million passenger miles. In Virginia, the average transit trip is a bit over 6 miles in length, and bike commuting has increased 89 percent over the last decade. 

There’s certainly the opening for building a transportation network that relies on more travel choice opportunities for our citizens such as intercity passenger rail and intercity bus for city-to-city travel; increased transit for intra-regional travel; and additional bike and pedestrian infrastructure to connect local destinations. Rail, transit, walking and biking are poised to play a greater role in our mobility, but it’s up to Virginians to let our decision makers know that’s what we want.

Here are a few opportunities to get involved:

The Virginia Department of Transportation (VDOT) is undergoing a study of the entire I-95 corridor from DC to NC. Learn more here. 

VHSR has launched a petition asking the VDOT to “make sure that passenger rail is a part of any solution to fix I-95” as part of their on-going study. You can sign our petition here.

An I-81 corridor advisory committee has been established and they are now meeting. Learn more here.