While reading your editorial about Highway 99 ("What if 99 were Interstate 7 or 9? Let's get answers," March 31), I found an error regarding the federally required spacing between interchanges. You stated it is a minimum of
half a mile, but it is one mile between regular interchanges and two miles between freeway interchanges. As you concluded, this requirement, if enforced, could result in eliminating a number of interchanges from Bakersfield to Sacramento.
EDWIN J. ERWIN
senior transportation planner, Caltrans, retired