As New Jersey lawmakers continue to argue over how best to fund the nearly bankrupt Transportation Trust Fund (TTF), a pool of money used to fix the state's roads and bridges, a new concern has been brought to the table.

Hand with gas pump and money (ThinkStock Images, ThinkStock)

With people driving less miles per day and more fuel efficient vehicles on the market, Senator Bob Gordon (D-Fair Lawn) is concerned that increasing the gas tax won't generate enough revenue to replenish the TTF.

"How do you address those who are concerned that just because of those kinds of changes there may be a long-term downward trend in revenue? Does that suggest that we need to supplement a gas tax with other forms of revenue?" asked Gordon during an Aug. 10 hearing of the Senate Legislative Oversight Committee.

The experts asked the questions were Forward New Jersey Chairman Tom Bracken and Utility and Transportation Contractors Association Executive Director Anthony Attanasio, both of whom have been pushing for a TTF funding solution for over a year.

Both agreed that while that might be a problem down the road, the focus needs to remain on funding a revenue source for the TTF.

"Right now that's not the issue," responded Bracken. "Down the road it might be an issue, but let's get down the road. Let's get to the point where we have to address the fact that maybe there's more electric cars, maybe there's more solar cars or whatever there are."

Bracken suggested that it will be up to future lawmakers to address any issues that might arise in terms of ensuring there is a sustainable and recurring revenue source to keep the TTF afloat.

"Let's get something going right now so we have something on the table that we can start with and the flexibility issue will kick in we'll deal with those in the future," Bracken said.

Attanasio suggested that tying a gas tax increase to the cost of living would work, but agreed with Bracken that it was not a discussion for right now. He noted that people always want to poke holes into revenue raisers that could solve the funding problem while the problem itself continues to grow.

"There always seems to be an excuse as to why not to raise the dedicated revenue for transportation infrastructure. Now it's fuel efficiency or fewer miles traveled is going to diminish the return on investment," Attanasio said.

Without a new funding source, the TTF is on pace to run out of money in June 2016.