For the most part, it is a winding road divided by a grassy median, but the part between Pasadena and Arcadia is a two-lane road.
It was built around the Pacific ElectricSierra Madreinterurban railway line.[1] The smaller and older portion of the road was originally Central Avenue in Sierra Madre, built some time in the 1860s or 1870s. The road forms a "┌" shape, starting at Elevado Avenue in Arcadia heading west and ends at Huntington Drive in San Marino. At Huntington Drive the road continues south as San Marino Avenue, then ends at Clary Avenue, near South Del Mar Avenue.
The section of Sierra Madre Boulevard between Washington Boulevard and Sierra Madre Villa Avenue is the end of the Tournament of Roses Parade. Floats are display the day after the Roses Parade on Sierra Madre Boulevard. Much of the boulevard in Pasadena has large grass median strip area between the lanes, that was part of the Pacific Electric street car in the past.