Several key Central Texas highway projects — including expansions of U.S. 183 in North Austin, U.S. 290 in Southwest Austin and Interstate 35 through the heart of the area — are once again in limbo after Gov. Greg Abbott and Lt. Gov. Dan Patrick last week staked out firm anti-toll positions. “Right now there’s a billion dollars worth of projects on hold, between 183 and Oak Hill,” said Mike Heiligenstein, executive director of the Central Texas Regional Mobility Authority. The I-35 project, estimated to cost $8 billion to add toll lanes and other improvements from Round Rock to Buda, was...