Thanks everyone for the feedback, it has been very helpful. I have make the corrections and I think the game is much better.
I added keyboard controls and better instructions, a speed boost and braking, and power-ups. If using the mouse you now change lanes by clicking on either side of the car rather than either side of the road.
Please let me know what you think.
Here is the link again: http://www.moonglowsoftware.com/games/taxi-driver/taxi-driver.html
Also, does anyone have any suggestions on the best places to publish an HTML5 game?
Thanks again. I really appreciate all the help and suggestions.