The commission wants details by January.
The Dallas Morning News reported Monday that the project is a prime candidate for financing similar to private toll deals nixed by the 2009 Legislature.
Lawmakers defeated attempts to extend the authority for so-called comprehensive development agreements with private companies to build roads, in exchange for toll revenue.
Commission member Ted Houghton of El Paso said Friday that authorities have got to use all of these innovative ways of building highways "or we won't be building."
Passthrough toll financing would have Texas promising to make payments to the firms based on the level of traffic use on the roadways.