I keep draining the battery

On the way to work, there is a tunnel I turn my lights on through the tunnel, and I keep draining the battery after I get to work because I forget to shut them off. There is no dummy bell to let you know they are still on (or at least if there's supposed to be one, it doesn't work). I finally put the jumper cables in the car so the next time this happens I don't have to wait an hour for Jim to come back to Berkeley from home to give me a charge.