The Speed Vest is described as "experimental clothing designed to create an environment in which bicyclists are respected as equal users of the roadway".

However, we agree with the Wired blog that suggests its more the perfect way to show off just how fast you can cycle the mean streets.

As you can see in the vid, that shows the vest on test in the States, it displays the cyclist's speed in 6-inch electroluminescent digits on the biker's back.

Currently "in development", there's no timescale provided for possible launch.