Have you ever walked or run to the beat of a song, or tapped along without even thinking about it?

This morning I was driving on the highway listening to Paranoid by Black Sabbath, cruising around 75 mph, and I noticed the beat of the song lined up perfectly with the lane markings passing by my car.

I started wondering if I could do that intentionally, so I skipped through a bunch of songs trying to match the beat to the lines (I learned pretty quickly that I couldn’t).

Then I wondered if this would work on any highway, and sure enough, there’s actually a standard for the length and spacing of lane markings in the US.

Anyway, I wanted to cheat, so I built this.

You type in a song, and it tells you what speed to drive so the beat lines up with the lane markings.

It uses the Deezer API to get a song’s BPM. If there’s no BPM available, it takes a sample from the audio preview and tries to estimate the BPM using PercivalBpmEstimator. I tried my best to minimize errors, but every once in a while the BPM of a song is still a little off.

Enjoy cruising to the beat, everyone!