(AP) – Missouri’s transportation chief is warning that the state won’t have enough money to maintain its roads in a few years.

The state’s construction budget for roads and bridges has fallen from about $1.3 billion annually five years ago to $685 million this year. Transportation Department Director Dave Nichols said Thursday that the annual road-and-bridge budget is projected to fall to about $325 million in 2017.

That’s considerably shy of the $485 million annually that Nichols says it takes to maintain the highway system in its current condition.

Nichols spoke at a transportation conference in Jefferson City hosted by the Missouri Chamber of Commerce and Industry.

Some of those at the conference are pushing a proposed ballot initiative that would ask voters to impose a 1-cent sales tax for transportation.