Forward and Reverse Circuit for a DC Motor

I've been wanting to build a robot that drove around and if it came to an object, it would sense it with a ping sensor and stop and turn the other way. I was in a hurry to build a circuit that would make a motor spin both ways, so it took a few hours to get it to work. I never looked to a schematic of an H-bridge. The hardest part was getting the transistors that controlled the two sets of transistors to work. The transistors do get hot, but I've never had one burn up.

Here is the schematic and the circuit on a breadboard on my robot.

Here is the video.