PTS Train Speeds and Stopping Distances — Questions and Answers
Question 1: Approximately how far does a train travelling at 125 mph require to stop under emergency braking?
- Around 500 metres
- Around 1,500 metres
- Around 2,500 metres (Correct answer)
- Around 4,000 metres
Correct answer: Around 2,500 metres
A train travelling at 125 mph (the UK East Coast Main Line maximum) requires approximately 2,500 metres (roughly 1.5 miles) to stop under emergency braking. This enormous stopping distance is why track workers cannot rely on a driver seeing them and stopping in time.
Question 2: A key reason track workers must NEVER rely on a train driver seeing them and stopping is:
- Drivers are not trained to use emergency brakes
- Train stopping distances are far too great to protect a worker who has been spotted late (Correct answer)
- Drivers are prohibited from sounding the horn near worksites
- Most trains travel with their headlights switched off during daylight
Correct answer: Train stopping distances are far too great to protect a worker who has been spotted late
Even at moderate speeds, the stopping distance of a train far exceeds what would be needed to protect a track worker. At 75 mph a train needs around 1,000 metres to stop. A driver spotting a worker at 200 metres cannot prevent a collision, which is why safe systems of work — not driver reaction — are the primary protection.
Question 3: Which statement about train speeds is CORRECT for someone working on or near the line?
- Trains always slow down near active worksites
- Trains may travel at full line speed even past an active worksite unless a specific speed restriction is in place (Correct answer)
- All trains automatically reduce to 20 mph when approaching a trackworker
- Drivers must stop their train before passing any person on the track
Correct answer: Trains may travel at full line speed even past an active worksite unless a specific speed restriction is in place
Unless a formal Temporary Speed Restriction (TSR) has been imposed as part of the Safe System of Work, trains may pass at full line speed. Track workers must never assume a train will slow down for them — protection comes from proper safe systems, not from train drivers.
Question 4: The concept of 'warning time' in PTS is directly related to train speeds because:
- Warning time determines when the driver must sound the horn
- Warning time must allow all workers to reach a position of safety before the train arrives (Correct answer)
- Warning time only applies to trains travelling above 100 mph
- Warning time is set by the train driver based on their visibility
Correct answer: Warning time must allow all workers to reach a position of safety before the train arrives
Warning time is calculated to give track workers sufficient time to stop work, collect tools, and reach a position of safety before a train arrives. Because trains at higher speeds cover distance faster, the required warning distance increases with line speed — making knowledge of train speeds central to understanding PTS.
Question 5: On a line with a 60 mph maximum speed, which best describes the stopping distance of a typical passenger train under emergency braking?
- Approximately 50–100 metres
- Approximately 200–300 metres
- Approximately 600–900 metres (Correct answer)
- Approximately 5,000 metres
Correct answer: Approximately 600–900 metres
At 60 mph a typical passenger train requires roughly 600–900 metres to stop under emergency braking. This is many times greater than the average human's reaction and movement time, reinforcing why warning systems and positions of safety — not driver braking — protect track workers.
Question 6: Why is it dangerous to assume a train you can see in the distance will stop before reaching you?
- Trains always accelerate when a driver sees an obstruction
- The train's stopping distance at speed may be many hundreds of metres greater than the current gap between you (Correct answer)
- Signal failures mean drivers receive no warning of workers on the track
- Train brakes are only effective on dry rail in daylight
Correct answer: The train's stopping distance at speed may be many hundreds of metres greater than the current gap between you
A train that appears distant may still be unable to stop before reaching your position. At 100 mph, for example, a train needs approximately 1,500–1,800 metres to stop. If the train is 800 metres away when you spot it, it cannot stop in time even if the driver applies emergency brakes immediately.
PTS Train Speeds and Stopping Distances
Approximately how far does a train travelling at 125 mph require to stop under emergency braking?