Miles of Interstates

The Federal Highway Administration has released their latest data on use of the interstate highway system. It contains a variety of state-by-state comparisons of the interstate system and how it is being used. FHWA leads with a list of the states with the most highly-traveled interstates and Georgia makes the cut.

America’s Ten Busiest States (by interstate vehicle-miles traveled) in 2011

California 84.681 billion
Texas 55.734 billion
Florida 34.689 billion
Ohio 31.389 billion
Illinois 31.033 billion
Georgia 28.467 billion
Virginia 24.062 billion
Pennsylvania 23.662 billion
North Carolina 21.241 billion
Michigan 20.707 billion


A state’s total VMT is a function of its population, its interstate lane miles, and the degree to which its residents rely on interstate highways for travel. Digging a little deeper into the Interstate Report and pulling some population numbers from the Census, it is possible to tease out these other variables.  After correcting for population, Georgia rises in the rankings to the second highest in both interstate VMT and interstate lane miles per person.

State 2011 VMT (billion miles) Population Lane Miles VMT Per Person Lane Miles Per 10,000 People
California 84.681 37,253,956 8,843 2273 2.37
Texas 55.734 25,145,561 15,266 2216 6.07
Florida 34.689 18,801,310 7,879 1845 4.19
Ohio 31.389 11,536,504 8,080 2721 7.00
Illinois 31.033 12,830,632 9,846 2419 7.67
Georgia 28.467 9,687,653 6,972 2938 7.20
Virginia 24.062 8,001,024 5,401 3007 6.75
Pennsylvania 23.662 12,702,379 7,820 1863 6.16
North Carolina 21.241 9,535,483 5,603 2228 5.88
Michigan 20.707 9,883,640 6,055 2095 6.13


This data is not particularly surprising – it is readily apparent that Georgians rely heavily on the interstate system for travel.  But the consequence is that Georgia is one of the most interstate-dependent states in the country.  And as a result, events that impair our interstates (like accidents and weather) are felt more acutely in Georgia than in other states. It is great to be first is many things, but dependence on a single form of travel is probably not one of them.








Highway Lanes for All?

As metro Atlanta increasingly focuses on managed highway lanes as a transportation strategy, a new report released by the Southern Environmental Law Center looks at whether income plays a role in use of the High Occupancy Toll (HOT) lanes. Atlanta_HOT_Lane_Report_Cover

A Highway for All? Economic Use Patterns for Atlanta’s HOT Lanes” confirms that drivers from higher-income ZIP codes are generally more likely to use the lanes. Atlanta’s I-85 HOT lanes have been criticized on equity grounds and even nicknamed “Lexus Lanes,” based on the assumption that higher income drivers are more likely to pay the toll to use these lanes. This report, however, is the first to actually examine driver data to test the relationship between income and use.

The report analyzes transaction data for the I-85 toll lanes and finds a positive relationship between the median income of drivers’ ZIP codes and of the ZIP code’s per capita HOT lane use.  Although income is not the only factor influencing use, the clear relationship between income and use is consistent with similar research on other projects around the country.

When approving the I-85 HOT Lanes in 2010, the Federal Highway Administration committed to conduct an analysis of the social equity impacts of the project after one year of operation, but no such study has been completed. In the meantime, several other managed lanes costing over $1 billion are in the plans for metro Atlanta, and transportation officials have described managed lanes as the foundation for the region’s long-term transportation plan.

In addition to analyzing user data, the report outlines a number of mitigation policies for the I-85 HOT lanes and future managed lanes to better allocate the benefits across all income groups. These include:

  • Maximize carpool access;
  • Minimize state funding for variable toll lane projects;
  • Use toll revenue to subsidize parallel transit service; and
  • Institute a toll credit program to provide minimum access for all registered users.

A copy of the report can be downloaded here.

A Streetcar Powered by Powerade?

A study committee of the Georgia Senate recently met to consider changes to Georgia’s public-private partnership process. Public-private partnerships, or P3s, are often touted as a way to leverage the efficiencies, expertise, and resources of the private sector in delivering public infrastructure projects. P3s also offer the vague promise of building public projects with someone else’s money – an  obviously appealing outcome but one that comes with a steep price.

After reworking the state’s P3 law in 2009, Georgia is now moving forward on its first large-scale transportation P3 in the Northwest Corridor managed lane project. The Northwest Corridor project’s convoluted history illustrates some of the challenges of P3s: the project’s procurement was cancelled and money was left on the table when the private partner wanted the state to turn over control of transportation in that corridor.

But as the Georgia Senate ponders new ways to access the private sector (and private funding), Streetsblog reviews a number of examples where private companies have led the way on non-roadway projects. For example:

  • Apple invested $4 million into renovating a transit station near its new store;
  • New Balance is funding a new commuter rail station as part of its corporate headquarters complex; and
  • Amazon building bike lanes in front of its new office in Seattle.

Responsible corporate citizens have helped pay for transportation infrastructure in the past, often through CIDs or other intermediaries.  But these new examples illustrate how companies are getting into the transportation game by directly funding projects. Perhaps the study committee’s next meeting should suggest a Home Depot BRT line or a Coca-Cola streetcar extension.

Clustering for Dollars

The Atlantic Cities blog has a post on the latest attempt to quantify and calculate the economic value of transit service. The post focuses on research by Daniel Chatman of the University of California at Berkeley on the economic value of agglomeration (noun, the act or process of gathering into a mass) triggered by investment in transit. The economic value of this transit-oriented agglomeration “could be worth anywhere from $1.5 million to $1.8 billion a year, depending on the size of the city. And the bigger the city, they find, the bigger the agglomeration benefit of expanding transit.”

Agglomeration adds economic value by improving access to labor (more people closer together means more opportunity to find good employees/employment) and improving the exchange of information (more people closer together means more opportunity to exchange ideas).  Transit facilitates agglomeration by allowing people and activities to cluster together and more conveniently access each other.

The blog highlights some additional facts and figures on the value of agglomeration:

Every time a metro area added about 4 seats to rails and buses per 1,000 residents, the central city ended up with 320 more employees per square mile — an increase of 19 percent. Adding 85 rail miles delivered a 7 percent increase. A 10 percent expansion in transit service (by adding either rail and bus seats or rail miles) produced a wage increase between $53 and $194 per worker per year in the city center. The gross metropolitan product rose between 1 and 2 percent, too.

A 2007 study out of UGA estimates MARTA’s annual economic impact in Georgia to be $2.1 billion.  Chatman’s research suggests that MARTA’s agglomeration likely makes its economic value even higher.

Transit Space Race

Reconnecting America has released a new interactive website titled “Transit Space Race 2013.” The site identifies and details the status of transit projects under construction or in development around the country.

Reconnecting America's Transit Space Race 2013

Reconnecting America’s Transit Space Race 2013

Atlanta’s representation on the list is pretty impressive, with 15 listed projects.  But the “status” column paints a different picture, as only the Downtown Streetcar project is “Under Construction” and many of the other projects are characterized as “Future Plans” or “Stalled.”


Management of Congestion?

Although it has received less attention than the projects on the north side of town, Georgia DOT announced it has completed its environmental review and is moving forward with a managed lane project on I-75 South.  The project would add two reversible managed lanes to the Interstate in Henry and Clayton Counties, allowing toll paying drivers better travel conditions when headed north in the morning and south in the evening. ARC officials recently described managed lane projects like this one as the “foundation of our long-range plan.” From the perspective of financial commitment that certainly is the case:  initially budgeted at $150 million, bids for the I-75 South project came in well over that amount. Combined with the Northwest Corridor project ($800+ million), the region is set to bet big on managed lanes in 2013-2014.

So what exactly should we expect from this project? Buried deep in the appendices to the project’s Environmental Assessment are two graphs showing how much these lanes are projected to improve travel conditions.

2015 Travel Time Estimate

2015 Travel Time Estimate

2035 Travel Time Estimate

2035 Travel Time Estimate

The first graph estimates the time it will take to travel the length of the project at rush hour in 2015 under three conditions: if the project is not built (“No Build”), for the tolled lanes with the project (“express lanes”), and for the untolled lanes with the project (“GP lanes”).  The second graph provides the same information, only for the year 2035.

In both graphs, the tolled lanes provide a clear improvement over doing nothing.  But they show that the project’s benefits for the untolled lanes are expected to be much more modest.  In 2015, when the project is slated to open, the toll lane trip will be 6.6-8.8 minutes faster than building nothing but the untolled lanes will only improve by 2.8-3.0 minutes.  In 2035, the toll lanes are projected to be 9.3-12.2 minutes faster but the untolled lanes 3.4-3.8 minutes faster.

Two other numbers are important here.  First, those time savings are spread over a roughly 12 mile project. Second, the Environmental Assessment predicts that, on average, 10% of the drivers on the road will be using the tolled lanes and the rest will be in the untolled lanes.

So the deal struck here is $150+ million for 10% of drivers to save 9-12 minutes and 90% of drivers to save 3 minutes. What remains to be seen is whether Atlantans view this as sufficient bang for their buck.