Asphalt or concrete lanes? Both are used on 405 Freeway and elsewhere

Q. I was wondering why there are two different surface materials used in the construction of the new lanes on the 405 Freeway in Orange County. It makes for a rough ride in the areas where the two surface types adjoin. I’m sure it’s a common practice, but I’ve just noticed it on the 405 in the Fountain Valley/Westminster area with the recent completion of the freeway widening.
– John Doyle, Newport Beach
A. The ol’ wise one enjoys guiding the Honkmobile on a ribbon