All who have taken Smart Cycling know that the best way to trip signal lights with standard loop detectors marked by wires on the pavement is to place your tires tangent to the wires - Tires to the Wires! It works great for aluminum rims. However, carbon rims have low conduction properties and Tires to the Wires! generally will not work. Here is a tip that may help you carbon wheel folks. You can buy HVAC aluminum tape with adhesive at your h/w store (used to wrap pipes and vents) and cut a strip to place over your rim tape (even if you run tubeless). It has been reported to trip signals > 90% of the time. So you, too, can trip those signals now.

If you haven't yet been to Smart Cycling, this is what is shown 

It works by electromagenetic induction. For physics aficianados: Maxwell's equations (simpler, Faraday's Law)

Interesting idea! I initially thought that a ferro-magnetic metal was required to trip the sensors. But apparently any conductive material works. This link has some interesting details about how that works.

A few years ago, San Diego city estimated that about 1/3 of the 30,000 sensor loops were malfunctioning or non-operational. At the time, they were beginning a campaign to start fixing those. However, at an expected rate of fixing about 250 per year, it was expected that it would take up to 40 years to fix them all.

https://www.sandiegouniontribune.com/2022/07/30/new-san-diego-campaign-aims-to-reduce-traffic-by-replacing-broken-traffic-sensors-4/

Super interesting!  Question:  Are the non-circular zones as easy to visually detect as the circles?  I regularly notice the circular ones, which have that obvious circle showing, but maybe I'm overlooking the others.

Quote from: Cody Barnes on May 05, 2025, 04:21:19 PMInteresting idea! I initially thought that a ferro-magnetic metal was required to trip the sensors. But apparently any conductive material works.

Cody - Read the paragraph on page 3 of attached which starts "There is a common misconception that an object must be ferrous (include iron) to activate a traffic signal loop sensor, or that a ferrous object will perform better." Read Common Rim Materials paragraph at the end to show performance of aluminum as the conductor.

I haven't done this myself yet and ymmv (mine, too). Phil Young, head of the defunct local Wheelmen chapter, is the source of the 90% anecdote I mentioned at first and who shared this with me.

Quote from: Daniel Upton on May 05, 2025, 05:00:20 PMSuper interesting!  Question:  Are the non-circular zones as easy to visually detect as the circles?  I regularly notice the circular ones, which have that obvious circle showing, but maybe I'm overlooking the others.

Daniel - I've seen all loop wire geometries as indicated on our Wires to the Tires slide. The only time you can't see where the wires are is when a slurry seal overlay hides them. You have to guess where they are so it's nice if they put a stencil on there showing where the wheel goes (rare in SD County) or after they do a full pavement resurface where the wires need to be reset.