More than a year after Texas voters approved routing billions in state sales taxes to roads and bridges, some lawmakers are questioning whether the first payment of $5 billion should move forward as planned. Texans voted in 2015 to boost funding for state’s public roadways and bridges, which have strained under the state’s growing population. Proposition 7 — loudly cheered by top Texas leaders and supported by 83 percent of voters — changed the state constitution to route some taxes collected on car sales to the State Highway Fund. But in an unusually tightfisted legislative session, some Texas lawmakers are...