Nobody uses RS485 drivers these days, because besides the driver itself you need other external components to really make it work. It's not really an issue of fault tolerant or not, the CAN protocol handles most errors anyway transparent to the user. Have a look at the 82C251 chip for expl.

Atmel has a nice slide show about CAN basics, (CAN tutorial)

http://www.atmel.com/atmel/products/prod73.htm

http://www.atmel.com/atmel/acr...3c08be.pdf

have fun

Werner