The "Inland Empire" region of Southern California - Riverside and San Bernardino counties - achieved a dubious distinction the other day. The Texas Transportation Institute elevated, if that's the word, the region into the list of the nation's five most traffic-congested areas - and it found itself in familiar company. The adjacent Los Angeles region (including portions of Orange and Ventura counties) retained its long-standing title as the nation's most congested, and the San Francisco Bay Area continued in its No. 2 ranking. Understanding California's dominance of the traffic jam sweepstakes doesn't take a degree in astrophysics. Simple arithmetic will...