Update 6:09 p.m.: SFMTA spokesperson Paul Rose said “this is a low cost measure to remind and prevent auto drivers from using transit only lanes,” and that the agency will implement the treatments on these street segments this week:

a. 3rd Street between Townsend and Jessie streets
b. Geary/O’Farrell streets between Market and Gough streets – (Note: segments between Grant and Powell will not be painted due to ongoing Central Subway construction)
c. Market Street inbound between  5^th and 12^th streets and outbound between 8^th Street and Van Ness Avenue.

The transit-only lane on Third Street, which tends to have an awful lot of cars in it, got some red paint this week to emphasize what the stenciled paint already says: “Bus Only.” The paint was added to a stretch approaching Bryant Street, where drivers are allowed to cross the bus lane to make a right turn, but not sit in it and block the 30, 45, and 8X lines.

The dashed treatment appears to denote a “merge zone,” similar to the green paint treatments added to bike lanes where drivers can cross, signaling to watch for people on bikes. It’s the first time the SFMTA has added such a treatment to a transit lane. Solid red paint has been used to highlight rail-only lanes on Church Street and the southern stretch of Third where the T-line runs.

We’ll see how far this goes to getting drivers to respect the transit lane. Certainly, it won’t happen without serious enforcement. The blockages are a real problem for Muni riders headed from SoMa to the Financial District and North Beach. Last July, Streetsblog reader Mike Sonn tweeted that he was waiting for his bus near this location when the bus passed him because drivers were blocking the path to the stop.