Decide whether to drive before you decide where to go

A typhoon or a heavy-rain forecast can change a rental-car day quickly. The safest plan is not to treat your booking, hotel reservation, or navigation estimate as a reason to leave. Instead, make a fresh decision before departure and again whenever conditions change. Start with the Japan Meteorological Agency (JMA) weather warnings. JMA explains that an advisory is issued when heavy rain or strong wind may cause damage, while a warning signals that a serious disaster may occur. An emergency warning indicates the strong possibility of a devastating event. These labels are not a driving-permission scale: local evacuation instructions and safety information take priority over sightseeing plans.

For a visitor, the practical question is simple: can this journey still be made without putting people, the car, or emergency responders at unnecessary risk? If the answer is uncertain, postpone, stay where you are, or choose another safe arrangement. Do not wait for a favorite attraction to close before reassessing. Conditions can differ sharply between the city where you collected the car, a mountain road, and a coastal destination.

Check weather risk and road status separately

Weather information tells you about a hazard; it does not confirm that a particular road is passable. Use JMA’s typhoon information, warnings, and risk maps to understand the expected rain, wind, and local risk. Then check the route itself. The Ministry of Land, Infrastructure, Transport and Tourism (MLIT) disaster portal links to the Japan Road Traffic Information Center, passable-road maps, and road-weather or traffic-control information. For expressways, Drive Traffic displays real-time closures and restrictions. A clear-looking navigation route is not evidence that a road remains open.

Make the two checks just before leaving, not only the night before. Repeat them after a long stop, after a warning update, or before you enter an expressway. Save your accommodation address and the rental company’s contact details offline. If mobile service becomes unreliable, you should still know where you are trying to return to or stay safely.

• Weather: Check the latest JMA warning or advisory for every area on your route, not only the destination.
• Roads: Confirm closures, traffic controls, and passable-road information through official traffic sources.
• Local guidance: Follow instructions from municipalities, police, accommodation staff, and road operators.
• Rental plan: Keep enough time and fuel for a detour, a return journey, or an unplanned overnight stay.

Know when the sensible choice is not to continue

Do not drive into a road covered by water, around a closure, or onto a route that officials say is restricted. Do not assume that a vehicle ahead has proved the road safe. In strong wind, rain, poor visibility, or rapidly changing conditions, reduce speed early, leave a much larger following distance, keep both hands on the wheel, and avoid abrupt braking or steering. If driving no longer feels controlled, move to a safe, permitted place to stop and reassess; do not stop on an expressway except in an emergency.

Never make a U-turn or reverse on an expressway. If you miss an exit because a diversion is confusing, continue to the next safe exit and seek updated information. Your first task is to remain predictable to other drivers. Your second task is to find a lawful, safe place to change the plan. Weather can disrupt flights, trains, ferries, and roads at the same time, so a slower decision is often better than a hurried attempt to keep the original itinerary.

Build a flexible day, not a rigid itinerary

Before setting out, tell everyone in the car what will trigger a change of plan: an official warning, a road closure, worsening visibility, an evacuation instruction, or driver fatigue. Give each planned leg a safe fallback such as returning to your accommodation, remaining at a service area only when it is safe and permitted, or contacting the rental company for assistance. Japan National Tourism Organization’s Safety Tips page links travelers to the latest JMA warnings and practical disaster information.

A rental car is useful because it gives you options; it does not remove weather risk. Check official information, separate forecast from road status, and be ready to delay or cancel a drive. That approach protects your trip and gives you the best chance of enjoying the road when conditions are genuinely safe again.