AUSTIN, Texas -- A top official at the Texas Department of Transportation says the future of transportation funding in Texas is bleak because of aging highways, shrinking tax revenues and inflation.

James Bass testified before the House Appropriations and Transportation Committees, which is reviewing the problems they'll face when the Legislature meets again next year.

Lawmakers fund Texas highways with a combination of federal money, fuel taxes, government bonds and contracts with private companies. But lawmakers have not raised fuel taxes since 1993 and more fuel efficient vehicles means revenues are not keeping up. Privately-operated toll roads have also become unpopular.

Bass discussed another options to improve highway funding by adjusting the fuel tax. He said under the current system, transportation funding will become a critical problem in 2015.