Driving in Japan During Typhoon Season: Essential Expressway Safety and Planning Tips

Renting a car and exploring Japan at your own pace is an incredible experience, but it requires careful preparation if you are traveling during the late summer and autumn. This period is known as typhoon season in Japan, and these massive tropical storms can severely impact travel plans and create hazardous driving conditions. Japanese expressways are engineered to high safety standards, but the extreme winds and torrential rain brought by a typhoon demand maximum respect and caution from drivers. If you plan to drive in Japan between August and October, this guide will provide you with the essential safety tips, planning strategies, and emergency protocols you need to navigate the expressways safely during severe weather.

Understanding Typhoon Season in Japan

Before you get behind the wheel of a rental car, it is crucial to understand what a typhoon is, when they typically occur, and how they specifically affect the country’s highway infrastructure.

When is Typhoon Season and What to Expect

Typhoons (known as “taifu” in Japanese) are powerful tropical cyclones similar to hurricanes in the Atlantic. The official typhoon season in Japan technically runs from May to October, but the peak months—when storms are most likely to make landfall and cause significant disruption—are August and September. During this peak period, the country can experience several typhoons, ranging from relatively mild storms that bring a day of heavy rain, to massive, slow-moving systems that cause widespread flooding and structural damage.

When a severe typhoon approaches the Japanese archipelago, the impact on transportation is immediate and profound. Airlines will ground flights, the Shinkansen (bullet trains) will suspend operations, and driving becomes incredibly hazardous. A typhoon brings two primary dangers for drivers: torrential, blinding rain that drastically reduces visibility and creates a high risk of hydroplaning, and extreme gale-force winds that can push vehicles across lanes or flip high-sided trucks.

For international tourists, the most important thing to understand is that a typhoon is not a standard rainstorm; it is a major weather event that requires you to alter your travel behavior. You should never underestimate the power of these storms or attempt to “power through” them on the highway to stick to a rigid itinerary. Flexibility and a willingness to prioritize safety over sightseeing are essential when renting a car during this season.

How Typhoons Affect the Expressway System

The Japanese expressway system, operated by NEXCO, is highly monitored and heavily regulated during severe weather. The operators prioritize human safety above all else, which means they will not hesitate to implement strict regulations when a typhoon approaches. The most common and immediate effect is the automatic reduction of speed limits. When heavy rain begins to fall, the digital speed limit signs above the highway will immediately drop from the standard 100 km/h to 80 km/h, and then down to 50 km/h as conditions worsen. These are not suggestions; they are legally enforced limits, and driving above them in a storm is exceptionally dangerous.

As the typhoon draws closer and wind speeds increase, NEXCO will begin preemptively closing sections of the expressway. The first areas to close are always the most vulnerable: coastal toll roads that are exposed to high waves (such as the Seisho Bypass), massive suspension bridges (like the Akashi Kaikyo Bridge connecting Honshu to Awaji Island), and high-elevation mountain passes where crosswinds are strongest.

These closures are communicated in real-time via the electronic information boards positioned along the highway and at the entrance toll gates. The boards will display flashing red text indicating a “Road Closure” (通行止). If you want to learn more about how to read these critical warning signs, our guide on Understanding Japanese Highway Electronic Signs: Red, Orange, and Green Messages Decoded is an essential resource for foreign drivers. Understanding that the highway system will physically prevent you from driving into the most dangerous areas should provide some peace of mind, provided you pay attention to the warnings.

Pre-Trip Planning and Weather Monitoring

The key to staying safe during typhoon season is proactive planning. The best way to survive a typhoon in a rental car is to avoid driving in it altogether by monitoring the weather forecasts accurately.

Checking Reliable English Weather Forecasts

The Japan Meteorological Agency (JMA) provides incredibly accurate, real-time tracking of typhoons. When a storm forms in the Pacific, the JMA projects its path, estimating when and where it will make landfall, often days in advance. As a tourist driving in Japan, you must make it a daily habit to check the weather forecast during the peak season.

Fortunately, the JMA operates a robust English-language website that provides detailed typhoon tracking maps. These maps display the storm’s current location, its projected path over the next 72 hours, and the “warning areas” (indicated by red circles) where severe winds and rain are expected. By checking this map every morning before you get in your car, you can see if your planned driving route intersects with the typhoon’s projected path.

In addition to the JMA website, you should also download reliable weather apps to your smartphone. The “Japan Official Travel App,” provided by the Japan National Tourism Organization (JNTO), pushes severe weather alerts and safety warnings in English directly to your phone based on your GPS location. Relying on accurate, English-language data allows you to make informed decisions about your itinerary before you are actually on the highway facing a torrential downpour.

Knowing When to Cancel Your Driving Plans

The most important safety skill you can exercise during typhoon season is knowing when to cancel your driving plans. If the JMA forecasts that a typhoon will pass directly over your location or your intended route, you must not attempt to drive. The risk of accidents, landslides, and becoming stranded on a closed expressway is simply too high.

If you are staying in a hotel and a typhoon is scheduled to hit that day, the absolute best course of action is to stay in your room. Do not attempt to drive to the next city on your itinerary just to keep your hotel reservation. Call the next hotel, explain that you are delaying your arrival due to the typhoon, and extend your stay at your current location if possible. Japanese hospitality businesses are highly accommodating during severe weather events, and they expect travelers to alter their plans.

If you are already on the road and you hear warnings that the typhoon is accelerating or changing course towards you, you should immediately look for a safe place to stop for the night. Use your English navigation apps to find a hotel in a nearby city, exit the expressway, and wait out the storm. Your itinerary can be adjusted; your safety cannot.

Driving Techniques for Heavy Rain and High Winds

If you are caught driving on the expressway as the outer bands of a typhoon begin to hit, or if you are driving through the heavy rain that follows a storm, you must drastically alter your driving techniques to remain safe.

Dealing with Hydroplaning and Reduced Visibility

The most immediate danger during a typhoon is the sheer volume of water falling on the road. Torrential rain can overwhelm the drainage systems on the expressway, leading to standing water on the asphalt. When you drive through standing water at high speeds, your tires lose contact with the road surface, and your car begins to skim across the water like a stone skipping across a pond. This is known as hydroplaning (or aquaplaning), and it results in a complete loss of steering and braking control.

To prevent hydroplaning, you must immediately reduce your speed. The moment the rain becomes heavy, drop your speed to 50 km/h or lower, regardless of the posted limit (unless the digital limit has already been lowered). Furthermore, avoid making any sudden steering movements or slamming on the brakes, as this can easily induce a spin. Ensure that your rental car’s tires have adequate tread before you leave the agency; bald tires will hydroplane much faster.

Reduced visibility is the second major hazard. The rain will be falling so heavily that your windshield wipers, even on the highest setting, will struggle to clear the glass. You must turn on your headlights (not just the daytime running lights) so that other drivers can see you through the spray. Increase your following distance significantly—leave at least four or five seconds of space between you and the car ahead. This gives you ample time to react if they brake suddenly. If visibility becomes so poor that you cannot see the lane markings, it is time to pull over at the nearest Service Area or Parking Area.

Navigating Crosswinds on Coastal Roads and Bridges

Typhoons bring ferocious winds that can easily destabilize a vehicle. This danger is magnified when you are driving on elevated sections of the expressway, crossing long bridges, or navigating coastal routes. The sudden gusts of crosswind can literally push your car into an adjacent lane or into the guardrail. High-sided vehicles, such as campervans or large SUVs, are particularly vulnerable to being flipped by these winds.

When driving in windy conditions, keep both hands firmly on the steering wheel at the 9 and 3 o’clock positions. You will need to make constant, small steering corrections to keep the car centered in your lane as the wind pushes against the side of the vehicle. Be exceptionally careful when exiting long tunnels. Inside the tunnel, you are protected from the wind, but the moment you emerge, a massive gust can hit your car from the side. Anticipate this by reducing your speed before you exit the tunnel and gripping the wheel tightly.

If you are driving on a coastal route like the Seisho Bypass or the Izu Peninsula roads, the combination of high winds and massive waves crashing against the sea wall is terrifying and dangerous. These are the roads that NEXCO will close first. If you find yourself on a coastal road as the winds pick up, exit as soon as possible and take an inland route. For more information on the hazards of these specific routes, read our guide on Driving the Izu Peninsula: Top Coastal Expressways and Scenic Rest Areas.

Highway Closures and Emergency Protocols

When the storm reaches its peak, the highway system will physically shut down to protect drivers. Knowing how to handle these closures and what to do in an emergency is vital.

Understanding Preemptive Expressway Closures

As mentioned earlier, NEXCO uses a system of preemptive closures to keep drivers off the most dangerous sections of the highway during a typhoon. These closures are not suggestions; the toll gates will physically lower their bars, and the ETC lanes will display red X’s, preventing any vehicles from entering the affected route.

If you are already driving on the expressway when a closure is implemented ahead of you, the electronic boards will flash a red message indicating a “通行止” (Closure). You will be forced to exit the highway at the Interchange immediately preceding the closed section. Highway patrol vehicles with flashing lights will often block the main route, directing all traffic onto the off-ramp.

When you are forced off the highway, you will find yourself on local roads. During a typhoon, these local roads will instantly become gridlocked with all the diverted highway traffic. Furthermore, local roads are far more susceptible to flooding and landslides than the elevated expressways. When you are forced to exit, do not attempt to use Google Maps to navigate a complex local detour to bypass the closure. The safest option is to find a local convenience store or a Michi-no-Eki (roadside station) parking lot, pull over safely, and wait for the weather to improve before continuing.

What to Do if You Get Stranded on the Highway

In extremely rare cases, a typhoon can cause a sudden landslide or a massive accident that blocks the expressway completely, leaving you stranded in your car between Interchanges. If you are stuck in standstill traffic during a severe storm and the road ahead is impassable, the absolute most important rule is to stay inside your vehicle.

Do not exit your car to see what is happening or to walk to a nearby Service Area. The winds during a typhoon can easily blow debris, such as tree branches or loose metal, across the highway at lethal speeds. Your rental car provides a sturdy, metal cage that protects you from this flying debris. Keep your seatbelt fastened, keep the engine running so you can use the air conditioning or heater, and listen to the highway radio (1620 kHz) for emergency instructions.

If your vehicle breaks down or you are involved in a collision during the storm, pull over to the left shoulder as far as possible. Turn on your hazard lights immediately. If you have an emergency flare (usually located in the passenger side footwell of Japanese cars), ignite it and place it behind your car only if there is a safe lull in the wind. Then, get back inside the car and call the police (110) or the rental car company’s emergency English hotline. For a comprehensive guide on handling accidents, review our article on Emergency on a Japanese Highway: What to Do and How to Call for Help (JAF).

Safe Refuges: Utilizing Service Areas During a Storm

If you are driving and the weather rapidly deteriorates, the Service Areas (SA) and Parking Areas (PA) along the expressway act as your primary safe havens.

Seeking Shelter at a Large SA or PA

The moment you feel the wind pushing your car forcefully or the rain becomes so heavy that your wipers are ineffective, you should pull into the very next rest stop. Do not try to push on to a specific destination. The large Service Areas on major routes like the Tomei or Meishin Expressways are massive, structurally sound buildings designed to withstand severe earthquakes and typhoons. They are the safest places you can be if you are caught on the road.

Once you park your car (try to park away from large trees or signs that could blow over), head inside the main building. These facilities have large food courts, comfortable seating areas, and clean restrooms where you can safely wait out the worst of the storm. The staff at these facilities are trained for emergencies and will often broadcast updates over the PA system if the highway is closing.

It is entirely acceptable to sit in the food court for several hours during a typhoon. You can purchase hot meals, charge your phone, and use the free Wi-Fi to monitor the JMA weather maps. Waiting in a brightly lit, comfortable Service Area is infinitely safer and less stressful than gripping the steering wheel in terror on a dark, flooded highway.

Stocking Up on Emergency Supplies

If the typhoon is particularly severe, you may end up spending the entire night parked at a Service Area. This is a common occurrence, and you will likely see many Japanese truck drivers and families doing exactly the same thing. To prepare for this possibility, you should utilize the convenience stores located inside the rest stop to stock up on essential supplies.

As soon as you decide to take shelter, head to the convenience store and purchase plenty of bottled water, non-perishable snacks (like bread, rice balls, and chocolate), and perhaps a portable battery charger for your smartphone if you do not have one in the car. It is also wise to purchase an umbrella or a cheap plastic raincoat, as you will inevitably need to walk from the main building back to your car to sleep.

Sleeping in your rental car at a Service Area during a storm is perfectly legal and heavily encouraged over driving in dangerous conditions. Recline your seat, crack the window slightly to prevent carbon monoxide buildup if you need to run the engine periodically for heat or AC, and wait for the morning.

Rental Car Insurance and Typhoon Damage

Driving in a severe storm dramatically increases the risk of damage to your rental vehicle. Understanding your insurance coverage before you encounter a typhoon is essential for your peace of mind.

Does Your Rental Insurance Cover Storm Damage?

When you rent a car in Japan, it comes with a basic level of mandatory insurance, but this often leaves you liable for a significant deductible (often up to 100,000 yen) in the event of an accident or damage. Because typhoons can cause unpredictable damage—such as flying debris cracking a windshield, or a flooded road ruining the engine—it is highly recommended that you purchase the maximum level of supplementary insurance offered by the rental agency.

This premium insurance is usually called Collision Damage Waiver (CDW) combined with Non-Operation Charge (NOC) coverage. When you purchase this full coverage package, you are generally protected from having to pay any out-of-pocket expenses if the car is damaged by storm debris or if you are involved in a hydroplaning accident, provided you were driving legally and following police instructions.

However, insurance policies in Japan often contain a “gross negligence” clause. If the police or the highway operator explicitly closed a road due to flooding, and you ignored the barricades and drove into the water, destroying the engine, the insurance company will likely refuse to cover the damage because you acted negligently. Always obey the road closures and the digital speed limits to ensure your insurance remains valid.

Documenting Damage and Contacting the Agency

If your rental car sustains damage during a typhoon—for example, if a branch falls on the roof while you are parked at a Service Area—you must document the damage immediately. Take clear, well-lit photos of the damage from multiple angles using your smartphone.

Next, you must contact the rental car company’s emergency hotline. Almost all major agencies (like Toyota Rent a Car, Nippon, or Orix) provide an English-speaking support number on the rental agreement. Explain the situation clearly, stating that the damage occurred during the typhoon. The agency will instruct you on how to proceed. In many cases, if the car is still drivable and safe, they will tell you to simply return it at the end of your rental period. If the car is undrivable, they will arrange for a tow truck, though wait times during a major storm will be exceptionally long.

Do not attempt to hide the damage or repair it yourself, and never return the car without reporting an incident, as this violates the rental contract and will invalidate your insurance coverage. Clear communication with the rental agency is the best way to handle storm-related damage smoothly.

Conclusion

Driving in Japan during typhoon season requires a fundamental shift in your travel mindset. While the Japanese expressway system is a marvel of modern engineering, it is not immune to the extreme forces of nature. The safety of you and your passengers must always take precedence over sticking to a rigid sightseeing itinerary. By maintaining a healthy respect for the power of these storms, you can navigate the season safely and confidently.

The key to a successful road trip during this period is vigilant proactive planning. Make checking the English weather forecasts from the Japan Meteorological Agency (JMA) a daily habit, and be fully prepared to cancel your driving plans and hunker down in a hotel if a typhoon is projected to cross your path. If you do find yourself on the road as conditions deteriorate, remember to drastically reduce your speed to prevent hydroplaning, grip the steering wheel firmly to combat crosswinds, and never attempt to bypass the flashing red road closure signs.

The extensive network of Service Areas and Parking Areas are your greatest assets during severe weather. They provide structurally safe, comfortable refuges where you can wait out the storm with access to food, restrooms, and emergency information. By utilizing these facilities, understanding your rental car insurance coverage, and prioritizing safety above all else, you can ensure that a late summer or autumn typhoon remains a minor inconvenience rather than a travel disaster.