When new residents of Houston first hit the roads, many come to the same realization: This is not normal. The highways are a labyrinthine mess. The motorists drive at extraordinarily high speed, often distracted. At night, drunk drivers weave in and out of traffic. Those factors lead to daily tragedy. Chronicle reporters knew the carnage was unusual. In 2016, they began investigating the scope of the problem. The findings: the greater Houston region was the nation's deadliest major metro area for roadway fatalities, with more than 640 deaths annually - or the equivalent of three fully loaded 737s crashing and killing all aboard, every year. They found declining speeding enforcement, even as deaths rose. They also discovered similar results with DWI and distracted driving enforcement.