Or could it be time to start cutting back on the first nap a bit?
I have the school run to contend with also. As time went on he'd be sleeping for an hour or so at 9ish and then it'd be a battle to get him down at 1ish. So I gradually cut his first nap back, first to 45 mins, then 30, then 20, etc etc until he was down to 1 nap.
This might be of some help?