Road Cycling - Common Sense Rules
In most countries bicyclists have all the rights and duties applicable to the driver of any other vehicle and can be penalized for violating traffic laws.

Always wear a helmet (law in some countries).

Ride on the correct side (with traffic flow) of the road for the country you are in. This means on the right in most countries and on the left in some such as Australia, England, New Zealand, and South Affrica, to name a few. Never ride against traffic.

In countries with traffic driving on the right side of the road, ride in the right lane, except when passing another vehicle, preparing for a left turn or avoiding hazards. In countries with traffic driving on the left, ride in the left lane, except when passing another vehicle, preparing for a right turn or avoiding hazards.

Ride on paved shoulders and bike lanes when present and free of hazards.

Ride no more than two abreast, returning to single-file when cars are passing. On curving canyon or mountain roads, play it safe and ride single file.

Obey traffic laws, signs, and signals.

Use hand signals to indicate left or right turns, slowing or stopping.

Use a headlight, taillight, and reflectors at night (law in some countries).

Make eye contact with drivers. Never assume motorists see you or that you have the right-of-way.

Expect the unexpected; your first responsibility is to be safe!
Courtesy of Bicycle Colorado
Additional Information
More details about cycling rules, common cycling sense, and other cycling-related information are available for download for each locale as listed below. To view the documents you will need Adobe Acrobat Reader.

Colorado
Rules of the Road
Shared Use Paths
Colorado Cycling Statutes
If You Crash
Parking Your Bicycle
Riding with Children
Equipment and Accessories
Terms Glossary
Courtesy of Bicycle Colorado