I like shorts with lots of pockets, so on longer rides where hiking shorts over biking shorts. I often wear a cotten tee-shirt under a biking jersey as well. The combination of layers is comfortable, especially in hot, humid weather, with the lower layer wicking away sweat, and the top layer staying dry.

Another advantage is when you end of sliding down the concrete, for any reason. The outer layer will get shredded, but the inner layer will survive. You get bruises, but no abrasions, in the areas covered with dual layers.