Automobiles make their way through the toll booth after crossing the Golden Gate Bridge in San Francisco. (John G. Mabanglo/European Pressphoto Agency)

But wait, you say, there are already tolls on the interstate system! So what’s the Obama administration talking about when they say they want to end the prohibition on interstate tolling and let states decide whether they want to impose tolls to pay for road and bridge repairs?

1. What does current federal law say?

It prohibits states or the federal government from establishing tolls on existing interstate highways. When states expand the system — think of the HOT lanes that opened last year in Virginia, and Maryland’s Intercounty Connector — they may receive permission to apply tolls on new lanes.

2. What is the White House proposing?

The administration wants to leave it to states to decide whether they want to toll their interstates. Money from new tolling would have to be used for repair and reconstruction of roadway systems, and the U.S. secretary of transportation would have to approve any new tolling plans for interstates.

“We believe that this is an area where the states have to make their own decisions. That’s a state decision under our proposal; it’s not a federal decision,” Transportation Secretary Anthony Foxx said Tuesday.

3. Why has this come up now?

Most of the money for the interstates and for most state highway maintenance and expansion has been paid for by state and federal gas taxes. Those funds have run low and are expected to continue to diminish, primarily because the cars we drive have become much more fuel-efficient. Though some states have increased their gas tax, the federal gas tax hasn’t gone up since 1993. The federal taxes go into a fund dedicated to transportation called the Highway Trust Fund. That fund is projected to go into the red by late July or early August. It’s up to Congress to figure out what to do about it, but states are in a pickle too, and the White House wants to give them the option of tolling.

4. What are the arguments for and against more tolling?

Few people want to see the cost of driving go up, but revenue is declining, and both the interstates — built in the 1950s and 1960s — and many of the road systems built during the suburban expansion of the same era also need help. Increased tolling is just one option, but there is strong opposition to it from those who argue that the interstates already have been paid for once, and from companies whose trucks would pay a heavy price. Support for the administration proposal comes from the International Bridge, Tunnel and Turnpike Association, an international association of toll facility owners and operators and businesses that serve them.

5. What’s the history behind tolling on the interstates?

The Federal Highway Administration explains it:

In the 1939 report to Congress, Toll Roads and Free Roads, the U.S. Bureau of Public Roads (BPR) rejected the toll option for financing interstate construction because most interstate corridors would not generate enough toll revenue to retire the bonds that would be issued to finance them.

That conclusion was called into question when the first segment of the Pennsylvania Turnpike opened on Oct. 1, 1940 [as a toll road]. It was an instant financial success. Based on this model, turnpikes appeared or were planned in Connecticut, Florida, Illinois, Indiana, Kansas, Kentucky, Maine, New Hampshire, New Jersey, New York, Oklahoma, Virginia and other states, often in corridors that had been designated as part of the interstate system in 1947. These roads were built without any federal-aid highway funds or other federal tax dollars.

In 1955-56, during consideration of financing options for the interstate system, Congress debated how to handle the turnpikes in interstate corridors. One option was to build toll-free interstate highways parallel to the turnpikes, but that would jeopardize the legitimate rights of the bondholders by diverting traffic from the turnpikes built with their investments. Repaying the bondholders and removing the tolls was another option, but it would divert hundreds of millions of dollars from the construction program without adding a single mile of highway to the interstate system.

After extensive debate, Congress decided in 1956 to authorize the BPR to incorporate toll facilities in the interstate system to ensure connectivity without added expense.

On Aug. 21, 1957, the BPR announced that it had added 2,100 miles of toll roads in 15 states to the interstate system.

The press release identified the facilities, with an asterisk indicating that the facility was in operation at the time:

Connecticut Turnpike, 98 miles: The section from the New York state line to Old Lyme, except the section at New Haven.

*Florida: Sunshine State Parkway, 41 miles: The northern portion, from Fort Pierce to Palm Beach.

Illinois: North Illinois Turnpike (Chicago-Rockford-Beloit), 47 miles: The northern portion, from south of Barrington to near Beloit.

Illinois: Tri-State Turnpike, 73 miles: From Calumet Expressway west and north around Chicago to the Wisconsin state line near U.S. 41, including a 5-mile spur near Deerfield to Edens Expressway.

*Indiana Turnpike, 151 miles: The entire route from the Ohio state line to the Illinois state line.

*Kansas Turnpike, 184 miles: From Kansas City to Topeka and from Emporia to the Oklahoma state line (the entire route except the Topeka-Emporia section).

*Kentucky Turnpike, 40 miles: The entire route from Louisville to Elizabethtown.

*Massachusetts Turnpike, 123 miles: From Boston to East Lee (the entire route except a short section at the west end).

*New Hampshire Turnpike, 15 miles: The entire route from Seabrook to Portsmouth.

*New Jersey Turnpike, 8 miles: The section from Newark Airport to Holland Tunnel.

*New York Thruway, 506 miles: The entire route from Yonkers to the Pennsylvania state line near Erie.

New York: Niagara Thruway, 8 miles: A section in Buffalo.

New York: New England Thruway, 4 miles: A section in New Rochelle.

*Ohio Turnpike, 173 miles: From the Indiana state line to southwest of Cleveland and from west of Youngstown to the Pennsylvania state line (the entire route except the Cleveland-Youngstown section).

*Oklahoma, Turner Turnpike, 177 miles: The entire route from Oklahoma City to the Missouri state line near Joplin.

*Pennsylvania Turnpike, 359 miles: From the Ohio state line to Bristol (the entire route except a short section at the eastern end).

Virginia: the Richmond-Petersburg toll road, 35 miles: The entire route from Richmond to Petersburg.

The inclusion of this mileage meant that interstate construction funds that would have been used for construction of toll-free interstate highways in these corridors could be used elsewhere to build interstate highways sooner than would otherwise have been possible.

Today, the 46,730-mile interstate system includes approximately 2,900 miles of turnpikes.

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