I just got back from a trip from Buttonwillow this weekend (for the track). Of course I was noticing all the road signs and I was wondering why the cities listed are different when you are going northbound vs. southbound. Our exit was Hwy 58 and going north it reads "Buttonwillow/McKittrick" but southbound it reads "Bakersfield." Although the reason may be since there is no exit for hwy 99 southbound you have to use 58 to get to Bakersfield. But I think it confuses some travelers. The guy in line in front of me at the motel thought he was in Bakersfield and I told him it's still 22 miles away. There are other exits as well that do this (northbound 166 reads "Taft/Maricopa" and southbound "Mettler/Maricopa").
Because if you were heading north, you'd probably have taken a different road to Bakersfield (CA-99, for example).
But, for southbound, CA-58 is the first logical cut-across road to Bakersfield. Hence, the signage.
Nobody would drive down to CA-99 to turn north to Bakersfield (at least I'd hope not) as that would be quite a detour.
Sykotyk