For what it's worth, Caltrans District 7 has done some extensive repaving on I-5 between Castaic grade/Violin Summit and the water information center exit; I saw what appeared to be the finished product in April while passing through there. This work was mostly necessitated by efforts to control a landslide issue that was exacerbated in the 2004-5 winter rains. But as a result, this section of 5 is in much better shape than adjacent sections. I'm not sure how this work was funded, possibly locally or maybe by the state. To that area's credit, there are active construction projects elsewhere on the route. To the south, I-5 has major work underway for the 5/14 HOV link (Measure M funding). To the immediate north the road was being worked on/repaved from around the LA-Kern County line north into the Grapevine itself, which is just north of Exit 210 Fort Tejon (not sure who's paying, maybe ARRA?). Further north, more repaving on the flat section of I-5 in Kern County/southern Central Valley was underway when I last went through there in April (around the California 43 interchange; no widening). All of this is significantly more work than I've seen on this stretch in the past 15-20 years.
Andy