Expressway Renewal Work | Joshinetsu Expressway Saku IC ~ Usui Karuizawa IC ( Line In-bound)

Saku IC - Usui Karuizawa IC (In-bound) 2026 March 2nd - August 6th

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RENEWAL

To pass on safety and security to the next generation
For a long time
Bridges, tunnels, etc.
Large-scale renewal work
We are carrying out.
Understanding and cooperation for construction
Thank you.

Regulations

Lane regulation (example)

Please note that during construction, traffic lane restrictions will vary depending on the day.
Due to regulations, special vehicles with a width of 3.0m or more cannot pass through.
As a measure to prevent congestion, the climbing lane before the construction site may be restricted.

section

E18 Joshinetsu Expressway 　
Saku IC - Usui Karuizawa IC (In-bound)

period

Monday, March 2, 2026
~ August 6, 2026 (Thursday)

All-day lane restrictions
Days when traffic jams of 5km or more are predicted

All day restrictions will be applied on Saturdays, Sundays and public holidays.
The construction period may change depending on the weather and work progress.

Congestion Forecast

Construction details

In order to make the structure stronger for tunnels that are subject to excessive force from the surrounding area, inverts ^* are installed to improve stability.

Construction contents Invert installation

Invert is to prevent deformation by installing semicircular concrete at the bottom of the road surface and making the tunnel shape circular.

By replacing the deteriorated existing concrete deck ^* with a new deck, Expressway will be reborn as a safe and comfortable one.

A deck is a structural member that directly supports automobiles passing through bridges and transmits the load to the girder.

Precautions when using

Traffic congestion is expected, so please allow yourself plenty of time when traveling.

Requests when passing special vehicles
Due to this traffic regulation, Special vehicles exceeding 3.0m in width cannot pass.
Customers using the service, please take a detour to the surrounding roads.
Also, please note that if you have obtained a special vehicle traffic permit (*) only for Expressway routes, you will also need to obtain a permit for general roads.

*What is special vehicle passage permission?
Based on the Road Law and Vehicle Restriction Ordinance, this is a permit required for special vehicles that exceed general restrictions (length, weight, vehicle width, etc.) to pass on public roads.

The maximum speed is limited to 50km / h in the restricted section.

Please check the traffic information in advance and leave with plenty of time.
Please be aware that lane widths and shoulder widths may be narrower.

If a traffic jam occurs, please turn on the hazard lamp at the end and signal the following vehicle to help prevent a rear-end collision.

Vehicles for construction work may enter and leave the area around the construction site, so please be careful when traveling ahead.

During the construction period, we will provide construction regulation information using road information boards, road signs, and simple information boards, and call attention to drive safely. Before riding, please check the above information before riding safely.