Kevin Balke, a research engineer at the Texas A&M University Transportation Institute, says that while smart lights can be particularly beneficial for some cities, others are so jammed that only a sharp reduction in the number of cars on the road will make a meaningful difference.

Project Goal: Engineer E. coli to convert carbon dioxide and electrical energy into ingredients for iso-octane, a fuel that can be applied to existing fuel infrastructure for U.S. transportation.

Mr. Miyamoto, the Japanese engineer, described a nation in chaos as the quake also damaged or disabled many elements of the transportation system.