This is for those who ride bicycles. DO NOT RIDE ON THE LEFT SIDE OF THE ROAD!!!
You're on a vehicle. You are required by law to follow the traffic laws. That includes riding with traffic, not against it.
I just took a short 6 mile ride, and saw three different cyclists riding against traffic. Not only is it illegal, it's just plain stupid. Anyone turning onto the roadway or crossing the roadway is looking for approaching traffic in the correct lane. Riding on the wrong side of the road is an excellent way to get yourself killed.
If you are one of these people, please read up on the cycling laws, safety information, and consider taking a cycling safety course before you get yourself injured or killed.
And if you don't wear a helmet, get one. Roughly 9,000 cyclists a year die from head injuries that could have been prevented/reduced by simply wearing a helmet. (They keep your head cooler too) About half of those killed are children under the age of 14.