I live in the depths of North Carolina...bicycles are considered a nuisance vehicle.
I was curious as to road width where I ride on a regular basis. So I put on my nice ANSI Class 2 Safety Vest and grabbed my measuring wheel. None of them have enough lane width IMHO for sharing. The main road in front of my property 22' from fog line to fog line, allowing 1' width for the center stripe. There is occasionally up to 20" of pavement to the right of the fog line, in some places there is none. The speed limit is 55mph and services over 6,000 vehicles per day on average. That volume will be increasing as they continue to build subdivisions further out.
The next road over (the one I have to take to get anywhere is barely 18' from fog line to fog line and has a double yellow line that is 12" wide
the edges of the road are broken down in many places reducing the lane width by 18" or more. These roads are 55 mph posted and have traffic volumes in the 3,000-4,000 vehicles per day range. The area is hilly, curvy and quite often you have limited sight distances. The main four lane into town is built to a better standard. It has 12' lanes with 6' shoulders and is a divided four lane. The posted speed limit is 55mph but average is probably 65mph+. Traffic volume is over 25,000 cars per day. For the most part I feel safe riding it, however I really wonder when I see banged up guard rails on the long straight sections...
As far as gauging the width, I figure a standard full sized pickup is around 7' wide a full sized semi 8' small sedans I give 5.5'. Regardless I am not a fan of lane sharing until they can stop drivers from all the distractions they currently have; cellphones, eating, video players on the dash, etc, etc. Driver training in the US needs to be drastically improved.
Aaron
