The secret to avoiding red lights during rush hour in Utah's largest city might be as simple as following a bus. Transportation officials have spent the past few years refining a system in which radio transmitters inside commuter buses talk directly to the traffic signals in the Salt Lake City area, requesting a few extra seconds of green when they approach. Congestion on these so-called smart streets is already noticeably smoother, but it's just a small preview of the high-tech upgrades that could be coming soon to roads across Utah and ultimately across the U.S. ....