RW>> Kinda like the 405 in LA. It's main purpose is to
 RW>> give access to the coastal area, while I-5 goes up
 RW>> the center of LA. 605 goes inland from the I-5.

 DC> I believe that the even numbered 3-digit roads are
 DC> "straight" Odd numbers are loops.

when in doubt, consult your nearest road atlas ;)

according to my Rand McNally Motor Carriers' Road Atlas...


     One and Two-Digit Signs
       Even - East/West
       Odd  - North/South

     Three-Digit Signs
       First digit even; route thru or around city
       First digit odd; spur into city

HTH  O:-)

)\/(ark