Recently I got into the major traffic jam. For about half an hour I was driving with the speed of about 3 km/h, slower than walking.
So here is my idea: like they make now hybrids of combustion engine and electric engine, - to make the similar hybrid of combustion engine and human powered vehicle.
In this case I could move my car with the help of human power by rotating with my hands some sort of levers, or pedals.
I would save a lot of fuel, and human power would be quite adequate for this low speed.
I put this idea into the pubic domain.