Design-build delivery rightfully has earned credit for unclogging many congested highways. But in a remote, rugged stretch of central California, design-build now is about to clear a different sort of traffic jam. In an innovative partnership teaming the U.S. Dept. of Energy, a private developer and an investor-owned utility, a contractor is completing an 84-mile, 500-kilovolt transmission line in the San Joaquin Valley that will relieve a longtime bottleneck on a grid segment called Path 15. The line’s 1,500 megawatts of additional transmission capacity will provide flexibility "to move generation up and down the state to meet the load demands,"...