Riding the City
Traffic Signals Were Timed for Cars and Riders Pay the Difference
Signal timing assumes a vehicle that accelerates hard and detects reliably. A bicycle does neither, which is why a city can feel like one long red.
The options around signal timing are set out side by side below, with the conditions that genuinely favour one over the other.
The difference in one place
- Green wave timings assume car acceleration and cruising speed.
- Inductive loop detectors may not register a bicycle at all.
- Waiting time at signals dominates urban journey time.
Where urban journey time goes
Over a short city journey the time spent stationary at junctions is frequently comparable to the time spent moving. That is true for every vehicle, but a bicycle loses proportionally more because it takes longer to regain speed afterwards. A rider stopping at a red also has to unclip or put a foot down, restart from stationary and accelerate a machine powered by legs.
The energy cost of that is real, which is why a route with many signals feels far more tiring than its distance suggests. Anything that reduces the number of stops therefore improves a bike journey more than riding faster between them would.
Green waves and the speed they assume
Signals along an arterial road are often coordinated so that a vehicle travelling at a particular speed meets a run of greens. That speed is chosen for motor traffic, and it is generally well above what a rider sustains on a loaded commuting bike.
A rider therefore falls out of the wave immediately and meets a red at every signal along the corridor. Some cities have introduced coordination timed for cycling speeds on designated routes, which changes the experience of a corridor completely. Where that exists it is usually signed or marked, and where it does not, the parallel back street often produces fewer stops.
The detector that does not see you
Many signals detect waiting vehicles using a loop of wire buried in the road surface, which senses metal passing over it. A bicycle contains far less metal than a car and may not disturb the field enough to register, particularly if positioned badly.
Come the wet months, the loop is usually most sensitive over the wire itself, which is why the cut lines in the tarmac are worth looking for. Positioning your wheels over the edge of the loop rather than in the middle of it improves the chances considerably. Where a signal genuinely never detects bicycles, reporting it to the highway authority is the mechanism that gets the sensitivity adjusted.
Waiting somewhere sensible
Where you stop at a red determines how visible you are and how the next few seconds unfold. Stopping in a position where the first driver behind can see you clearly, rather than tucked beside a large vehicle, is the practical priority. Some cities provide a marked area ahead of the stop line for bicycles, and its rules and availability differ widely between countries.
By the second week of riding, where such an area exists and is occupied by a vehicle, moving into it is often worse than staying visible where you are.
Positioning yourself for the direction you intend to travel, before the light changes, removes a manoeuvre from the busiest moment.
The pressure that produces red-light running
Long waits, signals that do not detect you and phases that give a few seconds of green produce genuine frustration. That frustration is the mechanism behind most red-light running by riders, which then becomes the entire public conversation about cycling. Some cities have introduced rules allowing riders to treat certain signals differently, and those rules vary enormously and remain contested.
Come the wet months, whatever the rule where you are, entering a junction against a signal removes the predictability that other road users are relying on. The design question underneath it is why the wait was long enough to make it tempting, which is a separate matter from the behaviour.
Anything structural — forks, steerer, brake mounts — is worth having a mechanic sign off.
What better timing looks like
Shorter overall cycle times mean less waiting for everyone, because nobody sits through a long phase serving another direction. Separate phases for turning traffic remove the conflict that produces the most serious junction collisions.
Come the wet months, a few seconds of early green for bicycles lets riders clear the junction before turning vehicles begin to move. Detection that works for bicycles, and buttons placed where a rider can reach them without dismounting, are unglamorous and effective. None of it requires new space, which is why signal timing is one of the cheapest improvements available to a city.
Side by side
| Consideration | What it means in practice |
|---|---|
| Where urban journey time goes | Green wave timings assume car acceleration and cruising speed. |
| Green waves and the speed they assume | Inductive loop detectors may not register a bicycle at all. |
| The detector that does not see you | Waiting time at signals dominates urban journey time. |
The takeaway
Count the stops rather than the kilometres, because that is what actually decides how long a city ride takes.
Fix the small rattle. Every large repair began as one.
Questions readers ask
Why does the light never change for me?
Many detectors are wire loops that sense metal, and a bicycle may not disturb the field enough. Look for the cut lines in the tarmac and position your wheels over the wire rather than in the middle. If it never works, report it.
What is a green wave?
Signals coordinated so a vehicle at a particular speed meets consecutive greens. The speed is usually set for motor traffic, so riders fall out of the wave. Some cities now run cycling-speed waves on designated routes.
