Hawaii officials say the timing of the tsunami warning and evacuation orders following this week's massive earthquake off Russia helped make for severe traffic congestion in some areas

While Monday's tsunami response was ultimately more of a drill than a true emergency, the traffic it triggered offered a real-time test of Oahu’s evacuation capacity — one that state officials admit was deeply strained.

Over a million Hawaii residents and visitors spent more than seven hours under threat of a potentially highly destructive tsunami Tuesday that triggered evacuations from low-lying coastal areas statewide.