Line 423 (Westlake Village - Calabasas - Encino - Downtown L.A. Express)
Proposed to operate all-day, seven-day-a-week service, replacing Line 161 and Line 427, with new route segment to connect with other lines at Warner Center hub. Not implemented due to objections from LADOT and the union representing MTA's drivers.
- LADOT proposed to break this line into two branches, effective August 2, 1999: Line "423A" would have served Newbury Park, Thousand Oaks, Agoura Hills and Calabasas and then operate directly to Downtown L.A., and Line "423B" would have operated from the Encino Park/Ride lots directly to Downtown, with half the service operated limited-stop on Victory Blvd. from Encino to Warner Center. Not implemented pending MTA service changes around the Metro Red Line extension to the Valley the following year, and then removed from consideration when the Metro Orange Line busway was constructed in 2005.
- Reverse-direction service (without Calabasas and Encino off-freeway segments, but with off-freeway segment to Warner Center) implemented as part of consent decree New Service Program February 16, 1998 as Line 422. Both lines were subsequently realigned to operate into the new Thousand Oaks Transit Center (423 in 2005, 422 in 2008).
- Route segment between Thousand Oaks Transit Center and Newbury Park eliminated August 1, 2010.