Recommended reading: Route 66 Adventure Handbook by Drew Knowles (Santa Monica Press).
GPS waypoints: GPS waypoint files are available at Route66maps.com. You can load them into your Garmin device and it will display a heart-shaped icon when you approach a historical Route 66 feature.
Legends of America has a lot of good online information and a state-by-state guide.
Ron Maskell, an Australian, did an amazing bicycle ride on most of Route 66 in 2012. His blog is a readable resource with excellent photography, and he has interesting observations about Americans from from a non-US viewpoint. Some quotes from his summary page were sobering:
Route 66 does not run through the pretty parts of America.
The roads between the towns often went through areas of severe rural poverty, lonely country, desolate country and towns that were either deprived, were looking extinction in the face or have died already.
Of the survivors, the older neighbourhoods were run-down and neglected, some almost derelict. Along the interstates, which are the scrub ticks draining the life from these towns, motel, Wal-Mart and service station development seems poorly planned and opportunistic. My impression was that the lack of government or official support is killing off Route 66. Many businesses are either struggling or closed down.Route 66 once extended into downtown Los Angeles via Figueroa Street and, in later years, continued to Santa Monica via Santa Monica Boulevard or Sunset. But the metropolitan sprawl of modern Los Angeles has gobbled up most (all?) traces of the old Route 66. There are plenty of dumpy buildings in Los Angeles that may date to the Route 66 era, but a visitor would be hard pressed to make much of a connection. I recommend you skip trying to find remnants of 66 in downtown Los Angeles and proceed east.
But moving east is equally frustrating because Pasadena, Arcadia, Monrovia, San Dimas, and Glendora have also suffered from extreme urban sprawl. 66 is essentially gone. But starting in Glendora, the map shows Route 66 proceeding along historic Foothill Boulevard. Well, the first few miles are solid modern strip with malls, gas stations, and condominium complexes. The waypoints on my Garmin GPS showed features along the way, but all were gone, overrun by modern malls and concrete.
Ascending the narrow Cajon Pass is difficult because parts of 66 have been overridden by the modern Interstate 15 (I-15). But once over the pass, we are in the desert and we can continue to look for Route 66 remains (to be continued).
Photographs taken with a Fuji X-E1 digital camera. I set it on black and white mode to fit the 1950s ambience of my expedition. I reprocessed some RAW files with PhotoNinja software. (Note, click any photograph to expand it to 1600 pixels wide.)