Elon Musk hates 405 Freeway traffic, offers money to speed widening
latimes.com
latimes.com
http://en.wikipedia.org/wiki/Braesss_paradox
Also, a typical road improvement project costs between one and five million dollars per mile. Based on the mean value, Musk's $50K contribution would add capacity to 106 feed of roadway.
Nice gesture, though.