11-304. When passing on the right is permitted
(a) The driver of a vehicle may overtake and pass upon the right of another vehicle only under the following conditions.
- When the vehicle overtaken is making or about to make a left turn;
- Upon a roadway with unobstructed pavement of sufficient width for two or more lines of vehicles moving lawfully in the direction being traveled by the overtaking vehicle.
(b) The driver of a vehicle may overtake and pass another vehicle upon the right only under conditions permitting such movement in safety. Such movement shall not be made by driving off the roadway.
Adjunct to discussion over at Google Plus on filtering through traffic with a bicycle.
The U.S. Uniform Vehicle Code is a model code published by the National Committee on Uniform Traffic Laws and Ordinances (NCUTLO). State governments adopt portions of the code as they see fit. The NCUTLO does this to promote a uniform traffic code across the United States so we know what to expect when driving (or cycling) across the country.