Photo/IllutrationA traffic sign shows the speed limit along the Chirihama Nagisa Driveway in Ishikawa Prefecture. (Toshiyuki Hayashi)

There's one beach in Japan that sun worshipers would do well to avoid ... as they could be run over.

The Chirihama Nagisa Driveway in Ishikawa Prefecture is the only stretch of sand in the nation that cars and tourist buses can freely use.

The fine quality of the sand makes the surface more solid rather than soft after seawater seeps in, allowing even large coaches to use the driveway.

In summer, traffic signs indicating a speed limit of 30 kph are placed along the driveway that stretches for about eight kilometers from Hakui to Hodatsushimizu facing the Sea of Japan.

The driveway is passable year-round, but since 1966 traffic signs have been posted for about a month each summer because of the heavier usage.

Nowadays, local government officials are voicing concerns about gradual erosion of the beach due to changes in the current.

In 1994, the beach was about 50 meters wide near the Chirihama rest house facility, but by 2011 the distance had narrowed to about 35 meters.

During high tide, waves lap the bottom of one of the traffic signs, and in some portions of the beach there is barely sufficient room for vehicles to pass each other in two directions.

Since 2011, the Ishikawa prefectural government has begun a project to restore Chirihama beach by dumping more sand in the area and constructing artificial reefs offshore to slow down sand erosion.