How long should a driving lesson be? is an hour to short? is two hours to long? 

I personally feel that two hours for a driving lesson is too long, for the pupil that length of time to concentrate while taking in information from the instructor is difficult to do. 

At the moment I offer 1 hour and one and a half hour lessons. I'm starting to think that one hour lessons can be a little short, by the time we have started and driven a short way I'm already thinking about bringing you back home again.

I'm thinking about just offering One and a half hour lessons. 

What do you think?