Bicycle Rating System

I've been biking to work on and off for the last 3 years. I've had quite a few reasons to do so:

  1. I don't want to take the bus
  2. I'd like to get some air
  3. It's good for me
  4. I like to get better at biking
  5. It's fun
  6. It's too far to walk

#3 and #4 are measurable through a number of methods. I could time myself, but that's a lot of work, and subject to environmental conditions. There are gadgets you can attach to your bike that tell you about your ride, but that is a lot of data with no inherent meaning. I also don't spend a lot of time off the bike thinking about how my rides are going, so any metric that requires me to do something outside the ride itself is out.

There are a number of emotional events that occur during a normal bike ride that can be integrated into a higher level evaluation of that ride:

Most of these measurements aren't useful in attaining a numerical measurement of a daily ride, since they're either subjective or coincidental. But two of them represent an action that offers an objective measurement: passing. When someone passes you (in broad strokes) they have proved that during this portion of the ride, they were the superior biker. The same goes when you pass someone

But that's not the end of the story; It's a very different thing to pass a couple in a tandem beach cruiser (singing 'tra-la-la') verses a pair tearing through the bike lane on their racing bikes while drafting within inches of one another. I'm not sure who is objectively having a "better ride" in that scenario, but I'm pretty sure who's the better biker. To differentiate, I've created 3 categories of bikers, each with an associated multiplier:

Additionally, we need a better definition of what it means for one rider to "pass" another. Otherwise, someone can zoom past you while you're stopped at a stoplight, turn right and vanish. Surely that shouldn't count for much. I've defined 4 zones relative to my perception while biking:

  1. Behind: You only know a biker is behind you when you either look back, or they catch up to you.
  2. Nearby: You can hear their gears or see them within 2 blocks in front of you
  3. Distant: You can see the biker at a distance, although they might be temporarily be hidden by obstacles. You still know where they are.
  4. Gone: You can't see them

Moving between a zone to a neighboring zone is zone distance 1. When either of you turn away from the other, the interaction is over. You can't catch up more, and they can't ride further away. Going from On the horizon in front of you to all the way behind you is a zone distance of 3. If someone comes from behind you, and you see them turn off when they are distant, the zone distance is -2. (start zone #) - (end zone #) = zone distance. Notably, you can have a non-zero zone distance with a rider you never actually pass. If you spot someone on the horizon, and you get right up close to them before one of you turns, that zone distance is 2. This is a "pass" even though you never actually overtake them.

Calculating Your Ride Value

Now we have all the tools required to calculate our daily ride value. When you get on the bike, your ride value is 0. Each time you "pass" another rider, you increase your ride value by (their multiplier) * (zone distance). Each time another rider "passes" you, decrease your ride value by (zone distance) / (their multiplier). Technically you're adding either way, but when someone passes you, the zone number will be negative.

For example, if the only bikers you see during your ride is a group of 3 PROs who pass you and then get near the horizon before you turn, your score is 0 - (2 / 2) * 3 = -3.

If you see 3 EABs and you chase them all down from the horizon until you overtake them, your score is 0 + (1 * 3) * 3 = 9.

If you only encounter one OLD biker, and he passes you and you lose him over the horizon, your score is 0 - (3 / 0.5) = -6.


There are obviously problems, like that one day when I encountered a bike race along the embarcadaro in San Francisco and lost a bazillion points. The system also doesn't do a good job is you don't encounter many other riders, or those riders are of vastly unequal skill, but that makes sense. It's a measurement of how effective a biker you are verses a replacement biker along the same route.

I estimate my average ride value as 2, what is yours?