Lucca is very flat; it is also walled, and the center of town (the bit within the walls) is essentially pedestrian only, similar to most Tuscan towns. This makes for a perfect setting for bicycles (le biciclette). Everyone rides their bike to work and there are bike rentals all around town.
I came across one place earlier today that rented bikes for €2.50 per hour, but if you only wanted the bike for 1/2 hour the cost was only €2.50. Capische?
Not Quite a Mid-Life Gap Year 