A type of bikeway popular in bicycling meccas like Copenhagen and Amsterdam is going to be tested on San Francisco's main thoroughfare starting next month. It's a design that transportation officials say will become more common over the next few years, as the city rolls out a number of long-awaited safe streets projects.

Monday, construction crews from the San Francisco Municipal Transportation Agency began working on the city's first raised bike lane, along two blocks of eastbound Market Street between 12th and Gough streets, where a green protected bike lane currently exists. Construction is expected to take about four weeks

A raised bike lane, separated from auto traffic, has a number of benefits, according to Mike Sallaberry, a senior engineer with the SFMTA's Livable Streets division. First, it raises the visibility of bike riders, improving their safety and comfort level, and is a draw for people who may feel cycling is a little intimidating.

SFMTA officials say this kind of bikeway also helps prevent vehicles from entering, but will also have to accommodate paratransit vehicles and taxis, which are allowed to enter the bike lanes to drop off passengers with disabilities. Planners also need to figure out how to deal with delivery trucks, and might consider creating drop-off zones.

Sallaberry explained that raised bike lanes haven't been done extensively in the United States, but that city planners have primarily looked to cities like Vancouver, Copenhagen and Amsterdam for best practices.