Signalling
Helmet

Signalling shouldn't cost cyclists control of their bike

Most bicycles, especially older ones, have no built-in turn indicators. Cyclists rely on arm signals, raising a hand from the handlebars to alert others — reducing control and increasing risk, particularly for older cyclists who find it hard to release the handlebar and turn to look behind before turning.

Swedish cyclists face a significantly higher risk than car occupants — 10 times greater chance of a fatal accident and 20 times higher likelihood of an injury requiring hospital treatment, per million kilometres travelled.

Looking for a wearable that matters

The team of five set out to build a wearable that could make a real difference, under the theme "wearable future product". We researched tangible products for inspiration, then each member brought at least three ideas to a brainstorming session.

Four concepts were shortlisted by dot voting — a solar-powered hat, a guitar that teaches by light and tone, a garbage bin that rewards correct sorting with music, and two connected music boxes for sending emotional messages between users. We used the Six Thinking Hats method to weigh each from multiple angles, then dot-voted again. The solar hat won, designed with a power bank and tactile buttons for a fan or speaker.

Figure 1a — Initial ideas

Figure 1b — The chosen initial idea

LEDs on the helmet, sensors on the gloves

The design pairs LED strips on the sides of the helmet with flex sensors on the gloves' index fingers. Bending the finger sends a signal to light the corresponding indicator — letting cyclists signal direction without leaving the handlebars.

Interviews with two cyclists, run before building the prototype, showed fingers move unintentionally while riding. To prevent accidental activation, we added a pressure sensor to the glove: cyclists press their thumb while raising the index finger to trigger the LED — a two-part gesture chosen for being intuitive to make.

Figure 3a — Sketch of the signalling helmet

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Figure 3b — Circuit built in Tinkercad

Figure 3c — Prototype, back

Figure 3d — Prototype, side

The first build used an Arduino UNO, a breadboard, wires, resistors, two flex sensors, two pressure sensors, and two LED strips. Sensors were tested on the breadboard first to measure resistance and set an activation threshold, then wired to the LED strips and attached to the helmet. Sensors were initially sewn into the gloves with conductive thread, but connections were unstable — we switched to soldering and gluing wires directly to the sensors, secured to the outside of the gloves for stability, and tuned the threshold repeatedly to avoid over-sensitivity.

Two changes from user testing

Two changes came directly out of user testing.

Signals other road users can read

Clear LED signals and simple finger gestures made the cyclist's intentions easier for other road users to understand. User testing also showed the need for vibration or visual feedback on the glove so cyclists can confirm when a signal is active.