Last week, Attorney General Greg Abbott concluded that state law does not allow the Texas Department of Transportation to transfer proceeds from a $3.2 billion payment made for the Texas 121 toll road project to a bank account controlled by local DFW-area governments.

This situation should alarm anyone who pays a toll to drive in the Metroplex.

Now their toll fees can be plundered by the upcoming Legislature and spent anywhere in the state, rather than being used as intended to build local transportation projects.

The effect of the attorney general’s ruling is that local governments will have to wait and hope the Legislature appropriates this money directly to them.

Until that appropriation becomes a reality and the money is returned to the DFW region, the funds will sit in an account controlled by the state.

Budget writers could use it for any purpose they desire.

While it may seem implausible that the Legislature would dare allocate these funds elsewhere, the public has good reason to be concerned.

The Texas Legislature routinely raids transportation funds that are otherwise protected by the state’s constitution.

Citizens expect that the transportation user fees they pay-whether tolls, vehicle registration fees, or gas taxes-will be used to alleviate traffic congestion; that is simply not the case.

According to the Transportation Department, the Legislature already diverted $1.57 billion from the state highway fund during the current budget cycle to pay for nonroad-building purposes such as historic preservation, narcotics enforcement and even certain Medicaid programs.

Besides diverting gas tax dollars away from fighting traffic congestion, the Legislature has a long history of using accounting tricks and gimmicks-such as deferred payments and raiding other dedicated funding sources, including sporting goods taxes and occupational licensing fees-to free up money to expand other government services.

Many of these diversions have been reined in during the past few years.

But we cannot ignore history’s lesson that politicians rarely pass up opportunities to spend money available to them-especially other people’s money.

When the Texas 121 project started, the DFW region was given assurances from the state that the money generated from this project would stay in the region for use on a list of projects developed by the regional transportation planning agency.

The region worked hard to fashion a plan whereby the North Texas Tollway Authority would build and operate Texas 121, and in turn the authority put forward a $3.2 billion payment to the state, which it raised from existing toll revenues, as well as from bonds that would be paid back from the tolls charged on users of the entire DFW toll road system.

After intense negotiations and public debate, the region trusted the state to follow through on its commitment.

As transparent consumption-based user fees, the gas tax and tolls are superior methods of generating funds to pay for highway construction because they are directly related to the service being used by the people.

If revenue from these sources is used elsewhere, lawmakers can no longer call them user fees, and have, in fact, created a new, arbitrary tax on its populace.

State lawmakers should remedy this situation as soon as possible, and take steps to ensure that the Legislature is never again given the opportunity to raid local funding.

Similarly, representatives and senators should end the practice of using state highway dollars as a slush fund for government services not related to building roads.

Justin Keener is vice president of policy and communications at the Texas Public Policy Foundation, a nonprofit, free-market research institute based in Austin.