LINCOLN, Neb. — Tractors, combines and fertilizer spreaders would have a little more freedom on Nebraska's roadways under a bill that won first-round approval from lawmakers Wednesday.

Senators advanced a bill, 39-0, that would relax weight and load restrictions for farm equipment on the state's roads.

Nebraska's restrictions are designed to keep heavy vehicles from damaging roads and bridges, but agricultural groups say the rules haven't kept pace with farming equipment and trucks that have grown larger and heavier over time.

"The industry has changed, and the equipment being used doesn't always fit" the rules, said Sen. Matt Williams of Gothenburg.

The rules have also created confusion among farmers and ranchers, some of whom have paid thousands of dollars in fines, and led to complaints that they are interpreted differently in different parts of the state.

Under the bill, weight and load restrictions would stay in place for bridges, and farm equipment would remain banned on Interstate 80.

The Nebraska Farm Bureau Federation and the Nebraska Cattlemen Assn. have identified the bill as one of their top priorities in this year's session. The Department of Roads, a part of Gov. Pete Ricketts' administration, has also endorsed the legislation.

"This is something we can do to relieve some of the pressure on businesses, especially ag businesses," said Sen. Jim Smith of Papillion, chairman of the Legislature's Transportation and Telecommunications Committee.

Several Nebraska counties still have concerns about the bill but will work with Smith to find a compromise before a second-round vote, said Larry Dix, executive director of the Nebraska Assn. of County Officials. Two additional votes are required before the bill goes to Ricketts.

The wear on roads tends to be worse in counties with large feedlots because trucks hauling manure generally weigh more than other farm trucks, Dix said.

Smith said one possible compromise could include an amendment that would allow local governments to maintain weight restrictions on roads that are especially vulnerable to damage from heavy vehicles.

Farmers and cattle owners have said they have an obvious incentive to use the roads sparingly so they can preserve them for their livelihood and families. Last year, the Nebraska Farm Bureau endorsed a 6-cent-per-gallon fuel tax increase to help pay for road and bridge maintenance.

Nebraska's bill is modeled after a 2014 Kansas law that exempted certain pieces of farm equipment from that state's highway weight and load restrictions. Iowa and Wisconsin have adopted similar laws.

The proposal was approved as part of a larger legislative package aimed at state roads.