What is 'shallow' that aims for the coexistence of bicycles and automobiles on the road?

The city of San Francisco has planned to add a bike-only road as part of the city's infrastructure. However, as a result of the city's budget being significantly revised due to the epidemic of the new coronavirus, it seems that 'shallow ', which indicates a shared lane for bicycles and automobiles, is being newly considered.

Sharrows, the bicycle infrastructure that doesn't work and nobody wants --macwright.com


Sharrow is a road sign that combines a bicycle and an arrow as shown below, and is named by combining 'Share' and 'Arrow'.


Jess J

Invented in 1993 by Denver City Bicycle Planner James Mackay, Shallow is an attempt to legalize bicycles to run in the middle of the road and allow cars and bicycles to share the road.

Episode 4: A Brief History Of The American Sharrow | The Bicycle Story

By drawing a bicycle icon on the roadway, Shallow not only makes the driver aware of the presence of the cyclist, but also prevents the bicycle from hitting the door of the parked car or the bicycle running on the shoulder of the road obstructing the progress of the car. It seems that there was also a purpose.

However, when I actually took the (PDF file) survey , the majority of the drivers I surveyed claimed to be unaware of Shallow. Due to the small number of drivers who responded to the questionnaire, the introduction of shallows was carried out as planned, but only 21% of the drivers surveyed noticed the shallow sign.

In an oral survey of about 200 San Francisco citizens and 50 cyclists, most cyclists said that the shallow sign was too small to be effective.

'None of the studies on shallows have clearly measured safety. We make statistical inferences like impression theory about the distance from the car to the bicycle and the position of the bicycle on the road,' McWright said. However, the actual safety is not strictly measured. '

A similar statement to McWright already existed in 2016, with the city of San Francisco planning to abolish shallows and build a new bike-only road. However, the city of San Francisco, which was forced to spend unexpectedly due to the response to the new coronavirus, is cutting the budget for the new design of the bicycle-only road and is trying to introduce shallows to the roads in the city again.

'Everyone who rides a cyclist knows that contact with a car is dangerous and dangerous. Non-legally binding shallows don't seem to help. Now it's dangerous on a quiet side road. It's time to drive the bike away and let it disappear into the asphalt. '

in Ride, Posted by log1i_yk