(MONEY Magazine) – ON A RECENT 4,500-MILE TRIP throughout the Midwest and Southwest, I took along your June report on speed traps and traffic fines in the 50 states. You helped save us money. I especially want to reiterate your warning to beware when traveling through Houston. The concentration of law enforcement was higher in Houston's Harris County than anywhere else in the trip. And speed limits are rigorously enforced there. Gary Nowitzke MONROE, MICH.