If wrong-way crashes were spread evenly across hours, roads, and drivers, preventing them would be nearly impossible — you would have to fix everything everywhere.
They are not spread evenly, and that is the most useful fact in this entire field.
The conditions that cluster
The AAA Foundation's analysis of fatal wrong-way crashes on divided highways from 2014 through 2023 identified elevated risk associated with dawn and dusk, nighttime, and rural areas. It also found higher risk among drivers who lived far from where the crash occurred, and drivers operating vehicles registered to someone else.
Combined with the elevated-risk driver groups — impaired, older, unlicensed — a coherent picture emerges rather than a scatter.
Why darkness matters so much here
Low light degrades exactly the capabilities a driver needs at an interchange.
Signs are harder to distinguish from their backgrounds. Ramp geometry that is obvious in daylight becomes ambiguous. Oncoming headlights create glare that further reduces the ability to read the scene. And the visual cue that most reliably signals a wrong-way entry — seeing the backs of signs rather than their faces — is much less noticeable when those signs are unlit.
Dawn and dusk add a specific problem of their own. These are transition periods where light levels are changing and the eye is adapting, and low sun angles can put glare directly in a driver's field of view at the moment they need to read a sign.
Why the hours compound
The conditions do not just co-occur — they interact.
Late-night hours are when impaired driving is most common. They are also when fatigue is highest, when traffic is lightest (so there are fewer other vehicles to demonstrate the correct path), and when a driver on an unfamiliar road is most likely to be relying on a navigation app rather than reading signage.
Each factor alone is manageable. A tired driver on a familiar road in daylight is fine. An unfamiliar interchange in daylight is fine. It is the stacking that produces the crash.
What "far from home" tells us
The finding that drivers involved in these crashes are frequently far from where they live is one of the more actionable pieces of the research.
Unfamiliarity means no memory of the interchange, no expectation of its geometry, and dependence on reading signage correctly the first time under time pressure. A local driver has a mental model. A visitor has whatever the road communicates in the moment.
That points directly at road design as the intervention. You cannot make visitors familiar. You can make interchanges legible enough that familiarity is not required.
How this shapes prevention
Concentrate detection where entries actually happen. Camera-based systems are deployed on specific corridors because coverage everywhere is not affordable. Prioritizing by risk is what makes a finite budget effective.
Prioritize lighting and signage upgrades at high-risk interchanges. The countermeasures that help most — illuminated signs, low-mounted signage, red retroreflective markers — specifically address low-light failure.
Focus awareness on the hours that matter. Messaging concentrated around late-night and holiday periods reaches people closer to when the risk is real.
Design for the unfamiliar driver. If an interchange only reads correctly to someone who already knows it, it is not finished.
The optimistic reading
The clustering is genuinely good news.
A problem distributed evenly across a road network would require rebuilding the network. A problem concentrated at identifiable interchanges, in identifiable hours, involving identifiable conditions can be attacked with finite resources and measured afterward.
Arizona's experience supports this. A detection system on a defined corridor has caught more than 100 wrong-way vehicles since 2018 — most of them at ramps, before they reached the freeway. That is what focused deployment against a concentrated risk looks like when it works.
Sources: AAA Foundation for Traffic Safety, Fatal Wrong-Way Crashes on Divided Highways, United States, 2014–2023 · Arizona Department of Transportation