(AP) — Assembly Speaker Robin Vos is challenging a host of special interest groups to solve Wisconsin's road funding problems by Monday.

Assembly and Senate Republicans are at loggerheads over how to pay for road projects in the face of a $1 billion shortfall in the state's transportation fund.

Assembly Republicans last week proposed imposing a new fee on heavy trucks. Wisconsin Manufacturers and Commerce, the state's largest business group, complained the fee would drive up business costs and a group of Senate Republicans refused to support the proposal.

Vos sent a letter to WMC, the Wisconsin Motor Carriers Association and a host of other groups and businesses Monday asking them to come up with another way to close the shortfall by Monday.

WMC and WMCA officials didn't immediately return messages.