---
title: "Schedule speed and factors affecting it"
subject: "Utilization of Electrical Energy"
chapter: 4
key: "semester_7/utilization_of_electrical_energy:schedule-speed-factors"
source: https://www.bctengineer.com/q/semester_7/utilization_of_electrical_energy/schedule-speed-factors
site: BCT Engineering
---

# Schedule speed and factors affecting it

Utilization of Electrical Energy · Chapter 4: Electric Traction

- Asked in: 2070 Asar
- Video: [Factors which affects the scheduled speed |Scheduled Speed| |Electric Traction & Control|](https://www.youtube.com/watch?v=Af3TKDjjviM) — Anish Vora
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/utilization_of_electrical_energy/schedule-speed-factors
- Whole chapter: https://www.bctengineer.com/md/semester_7/utilization_of_electrical_energy/chapter-4

## Question

What is the schedule speed of a traction system? Discuss the various factors affecting this speed.

## Short answer

Schedule speed is distance between stops divided by total time including stops (Vs = D/(Trun + Tstop)). Factors: acceleration/retardation (higher increases Vs), maximum speed (more impact on long runs), stop duration (longer stops reduce Vs), distance between stops (longer increases Vs), coasting (longer reduces Vs), gradient/curves, train resistance/load, motor characteristics/supply voltage. Urban service most affected by acceleration, braking, stop time; mainline by crest speed.

## Answer

**Schedule speed** is the ratio of the distance between two stops to the total time of the run **including the stop time**:
$$
V_s = \frac{D}{T_{run} + T_{stop}}
$$
It is lower than average speed and is the speed that matters to passengers and to timetable planning. A high schedule speed means fewer trains are needed for the same service.

#### Factors affecting schedule speed
1. **Acceleration and retardation:** higher acceleration and braking shorten the run time, especially for short distances (urban service), so schedule speed rises. They are limited by passenger comfort and adhesion.
2. **Maximum (crest) speed:** for a given distance and rates, a higher crest speed reduces running time. Its effect is larger on long runs (main line) than on short urban runs.
3. **Duration of stops:** schedule time includes stop time, so longer stops reduce schedule speed. The effect is large in urban service where stops are frequent.
4. **Distance between stops:** for the same acceleration, braking and crest speed, schedule speed increases with distance because acceleration and braking take a smaller share of the time.
5. **Coasting:** longer coasting saves energy but lowers average and schedule speed.
6. **Gradient and curves of track:** up-gradients and sharp curves force lower speeds.
7. **Train resistance and load:** heavier trains accelerate more slowly for the same motor power.
8. **Motor characteristic and supply voltage:** a drop in line voltage reduces motor speed and acceleration.

```text
 V | constant D, Vm
   |  /------\       higher alpha, beta  --> shorter T
   | /        \      longer stop time    --> lower Vs
   |/          \
   +------------\-- t
```

**Summary:** for urban service, acceleration, braking and stop time are the main factors; for main-line service, crest speed is the main factor.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is schedule speed?
   A. Distance divided by run time
   B. Maximum speed
   C. Distance divided by run time plus stop time
   D. Mean of Vm and Va
   Answer: C. Including stop time makes it lower than average speed. (Key point: Definition)

2. Why does higher acceleration raise schedule speed, especially in urban service?
   A. It lowers stop time
   B. It lowers resistance
   C. Run time shortens, mattering most for short distances
   D. It raises distance
   Answer: C. Acceleration and braking take a large share of short runs. (Key point: Acceleration effect)

3. What is the effect of longer coasting?
   A. Raises both
   B. Saves energy but lowers schedule speed
   C. No effect
   D. Raises speed, wastes energy
   Answer: B. Speed falls during coasting so run time increases. (Key point: Coasting)

## Related in Utilization of Electrical Energy

- [Schedule speed for a 2 km run (trapezoidal)](https://www.bctengineer.com/question.md?key=semester_7%2Futilization_of_electrical_energy%3Aschedule-speed-trapezoidal-2km-run) — Utilization of Electrical Energy, chapter 4, asked 3×
- [Schedule speed for a 1.5 km run (trapezoidal)](https://www.bctengineer.com/question.md?key=semester_7%2Futilization_of_electrical_energy%3Aschedule-speed-trapezoidal-1-5km-run) — Utilization of Electrical Energy, chapter 4, asked 3×
- [Schedule speed for a 2.5 km run (trapezoidal)](https://www.bctengineer.com/question.md?key=semester_7%2Futilization_of_electrical_energy%3Aschedule-speed-trapezoidal-2-5km-run) — Utilization of Electrical Energy, chapter 4, asked 3×
- [Acceleration, coasting retardation and schedule speed](https://www.bctengineer.com/question.md?key=semester_7%2Futilization_of_electrical_energy%3Atrain-48kmph-coasting-schedule-speed-stops) — Utilization of Electrical Energy, chapter 4
- [Crest, average and schedule speed; speed-time curve](https://www.bctengineer.com/question.md?key=semester_7%2Futilization_of_electrical_energy%3Acrest-average-schedule-speed-42kmph) — Utilization of Electrical Energy, chapter 4
- [Acceleration for 25 kmph schedule speed, 800 m stations](https://www.bctengineer.com/question.md?key=semester_7%2Futilization_of_electrical_energy%3Aacceleration-25kmph-800m-stations) — Utilization of Electrical Energy, chapter 4

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