As noted above, at least 15 states allow local governments to assess an additional gas tax. Allowing local option gas tax is a way for communities willing to tax themselves to solve transportation problems without involving other parts of the state, which may not have the same issues and may be unwilling to support a statewide tax increase. The local gas tax is an important part of a state's overall transportation funding.
The disadvantage of a local option gas tax is that rates may differ from jurisdiction to jurisdiction. Rate changes could cause consumer migration to non-taxing areas.