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.

Residents and visitors across the Hawaiian Islands were sent scrambling after a tsunami warning was sent out on Tuesday.