The Commute
Riding Harder Does Not Make a City Commute Much Shorter
Effort and arrival time are only loosely connected in traffic. The time you save between junctions is largely handed back at the next red light.
There is a short answer about commuting journey time and a useful one, and they are not the same. What follows is the useful one.
The short version
- Journey time in cities is dominated by stops rather than cruising speed.
- Air resistance rises steeply with speed, so extra effort buys little.
- Consistent moderate pace usually matches hard riding over short distances.
Where the time actually goes
A city commute consists of short bursts of riding separated by junctions, crossings, turning traffic and pedestrians. Time spent stationary and time spent accelerating back to speed together account for a large share of the journey.
Raising your cruising speed only shortens the riding portions, and it does nothing to the stationary ones. It can also mean arriving at a signal that has just changed, which converts your saved seconds into a longer wait. That is why riders who time their commutes carefully often find a large effort increase produces a small time saving.
The physics of going faster
At typical cycling speeds, most of the resistance you overcome is aerodynamic drag from pushing air out of the way. Drag force rises roughly with the square of speed, and the power needed to overcome it rises roughly with the cube. That means going meaningfully faster requires a great deal more power, which is why the effort feels disproportionate.
In the saddle, the same relationship explains why a headwind is so punishing and why drafting behind another rider saves so much. For a commuter the practical conclusion is that speed is expensive and buys progressively less.
What actually saves time
Choosing a route with fewer signalised junctions has a larger effect than riding harder on a busier one. Smooth riding that maintains momentum, rather than sprinting and braking, reduces both effort and time. Anticipating signals and traffic so you arrive rolling rather than stopped removes the acceleration cost entirely.
Leaving five minutes earlier is a more reliable way to arrive earlier than riding five minutes harder. Reducing time spent at each end, on locking, changing and faffing, often saves more than anything on the road.
The costs of riding hard
Higher effort produces more heat and more sweat, which is the thing most likely to make a commute impractical. It also produces fatigue that carries into the working day and into the return journey. Riding hard in traffic reduces your spare attention, which is the resource you most need for anticipating other road users.
Braking later and accelerating harder reduces your margin for the unexpected, and margin is what prevents incidents.
None of that argues against enjoying speed, only against assuming it is buying you time.
Momentum and how to keep it
Every stop costs the energy needed to get back up to speed, and in a city you may make dozens. Reading the signal sequence ahead lets you ease off and roll through rather than stopping and starting.
Choosing the correct gear before you slow down means you can accelerate away without straining the drivetrain. Looking well ahead rather than at the wheel in front gives you the information to do any of this. Riders who look further ahead consistently report an easier commute at the same average speed.
Range and charging figures are quoted under conditions nobody commutes in.
Consistency beats intensity
A commute you can do five days a week at a moderate pace is worth more than three fast ones and two by other means. Moderate pace also means less kit, less washing and fewer reasons to skip a day when the weather is poor. If you want the training benefit, take a longer route rather than a faster one on the same route.
Come the wet months, that gives you more time on the bike, which is the variable that most affects fitness, without the arrival problems. Treating the commute as transport and doing your hard riding separately is a distinction most long-term commuters end up making.
The takeaway
Save time by choosing the route and keeping momentum, not by pushing harder between red lights.
Most of riding well is being boring and predictable to everyone else on the road.
Questions readers ask
Would an e-bike make my commute much faster?
Usually less than expected in dense traffic, because stops dominate. What it reliably changes is effort, sweat and how hills feel, which is why people buy them.
Why does riding much harder save so little time?
Aerodynamic drag rises with the square of speed, so power demand climbs steeply, and in a city you hand much of the gain back at the next junction.
