Financial needs for road maintenance and improvement

In my planning job-project, I am interacting a fair amount with various representatives from the Maryland State Highway Administration. On the way to a field meeting yesterday, we were discussing monies for road improvements, transit, public participation, and the like.

he mentioned that earlier in the year there was a design-build conference in Baltimore, and these numbers were pronounced:

2 cents / mile = the average amount of money generated by gasoline excise taxes to support preservation and maintenance of the current road system

11 cents / mile = the amount needed to support preservation and maintenance of the current road system at high levels

20 cents - 30 cents / mile = the amount needed to support expansion programs, including the accommodation of bicyclists and pedestrians, placemaking improvements, transit, etc.