From our field notes
Jet Lag and Road Trips: How Long Should You Wait Before Driving?
Published 8 August 2026 · updated 8 August 2026 · 8 min read
A long-haul flight, a rental car counter, and the urge to make the most of the first day on the ground: that's usually where one of the most underrated risks of a road trip quietly begins. On the guide's farthest destinations — Japan, New Zealand, Australia, Peru, Mexico, Costa Rica, Canada — jet lag isn't just mild discomfort: it measurably impairs alertness and driving reflexes, sometimes as much as an illegal blood alcohol level. Here's what the research says, and how long to actually wait before getting behind the wheel depending on the destination.
Jet lag is a real driving risk, not just discomfort
After an overnight flight landing in the middle of local daytime, it's not unusual to have been awake for 18, 20, even 24 hours by the time you pick up the keys to a rental car. Sleep deprivation degrades cognitive performance and reflexes in a way that's directly comparable to alcohol: a landmark study by Dawson and Reid, published in 1997 in the journal Nature, established that after 17 hours of continuous wakefulness, performance impairment is equivalent to a blood alcohol concentration of 0.05%, and after 24 hours it reaches 0.10% — well above the legal driving limit in most countries (study available on Google Scholar).
Jet lag adds a second layer on top of that: beyond simple sleep debt, the internal biological clock stays set to the departure time zone for several days, disrupting alertness at hours when the body still 'believes' it should be asleep — typically late afternoon or evening local time, exactly when many travelers are still on the road heading to their accommodation.
Which of the guide's destinations cause real jet lag
Not all destinations are equal. Jet lag scales with the number of time zones crossed, and driving risk rises noticeably beyond a 5-to-6-hour difference from your home time zone.
| Destination | Approximate time difference (summer, from Western Europe) | Risk level on arrival |
|---|---|---|
| New Zealand | about +10 to +11 h | High |
| Japan | about +7 h | High |
| Australia (east coast) | about +8 h | High |
| Costa Rica | about -8 h | High |
| Mexico | about -7 to -8 h | High |
| Canada / United States | about -6 to -9 h depending on the coast | High |
| Peru | about -7 h | High |
| Chile | about -5 to -6 h | Moderate |
| Argentina | about -5 h | Moderate |
| Sri Lanka | about +3 h 30 | Moderate |
| Namibia, South Africa, Kenya, Tanzania | about +1 to +2 h | Low |
| Morocco, Iceland, Europe (Scotland, Norway, Greece, Spain, Portugal, Ireland) | 0 to -2 h | Low |
Eastbound or westbound: why direction changes the difficulty
Not all time differences feel the same. Traveling westbound (the Americas) lengthens the biological day, which matches the body's natural tendency to easily delay its internal clock — adjustment is generally faster. Traveling eastbound (Japan, New Zealand, Australia) shortens the biological day instead, a direction in which the internal clock adjusts more slowly — the body has to 'advance' its rhythm, which is physiologically harder.
A study by Chai and Flaherty, published in 2019 in the International Journal of Travel Medicine and Global Health, specifically examined the link between jet lag symptoms and road safety among international travelers. The authors note that travelers' own failure to recognize these symptoms — feeling fit to drive while their reflexes are measurably impaired — is an underappreciated road accident risk factor, particularly after an eastbound flight (study available on Google Scholar).
How long to wait before driving on arrival
There's no legal rule requiring a waiting period before driving after a long-haul flight — unlike alcohol, jet lag isn't measured by any roadside test. Caution is entirely down to how the traveler plans the trip.
| Time difference | Recommendation before driving |
|---|---|
| 0 to 2 h (Morocco, Iceland, Europe, Kenya, Tanzania) | No special jet-lag precaution needed, but avoid a long drive without sleep right after an overnight flight |
| 3 to 5 h (Chile, Argentina, Sri Lanka) | Get a full night's sleep before a long leg; keep the first drive under an hour |
| 6 to 8 h (Japan, Australia, Mexico, Costa Rica, Peru, Canada, United States) | Plan at least one night to adjust before hitting the road; book the first night's accommodation right next to the airport |
| 9 h or more (New Zealand) | Ideally plan 1 to 2 nights to adjust before a long driving leg, especially where the country also requires driving on the left |
Planning the first day to cut the risk without losing vacation time
A few simple adjustments to the itinerary cover most of the risk, without sacrificing a full day of the trip.
- Book the first night right next to the airport rather than several hours' drive away: the very first leg is often the riskiest.
- Avoid driving right after an overnight flight with no sleep, even if it's broad daylight on arrival — sleep debt doesn't show in the mirror.
- Alternate drivers on the first legs when traveling as a group, handing the wheel to whoever was least worn out by the flight.
- Get natural daylight exposure as soon as you arrive to help reset the internal clock faster, rather than heading straight into a darkened room.
- Skip alcohol and sleep aids on arrival night if a driving leg is planned early the next morning.
- Recognize the early signs of drowsy driving (repeated yawning, trouble focusing, brief lapses of attention) and stop immediately rather than trying to push on to the next stop.
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Before you go
Readers' questions
Is jet lag really dangerous behind the wheel, or just uncomfortable?
It's a real, measurable risk factor. A study published in Nature (Dawson and Reid, 1997) shows that after 17 hours of continuous wakefulness, reflex impairment equals a blood alcohol concentration of 0.05%, and after 24 hours it reaches 0.10% — well above the legal driving limit in most countries.
Should you always wait a full day before driving after a long-haul flight?
It depends on how many time zones you crossed. Under 2 to 3 hours of difference (Morocco, Iceland, southern Africa), no special precaution beyond a good night's sleep is needed. Beyond 6 hours (Japan, Australia, the Americas), planning at least one night to adjust before a long driving leg is a reasonable precaution.
Is it harder arriving eastbound or westbound?
Generally eastbound: the biological clock adjusts more slowly when it has to 'advance' its rhythm (as on a flight to Japan, Australia or New Zealand) than when it has to delay it (as on a flight to the Americas). A 2019 study published in the International Journal of Travel Medicine and Global Health identifies this as a road safety risk travelers themselves tend to underestimate.
Which of the guide's destinations cause the most jet lag from Western Europe?
New Zealand tops the list with 10 to 11 hours of difference, followed by Japan and Australia (about 7 to 8 hours), then destinations in the Americas such as Costa Rica, Mexico, Canada, the United States or Peru (6 to 9 hours depending on the region). By contrast, Namibia, South Africa, Morocco or the guide's European destinations involve almost no time difference at all.