| Visitors observing your model railway layout may | | | | a crash. That is why the yellow/amber warning |
| wonder why your trains slow to stop at signals. | | | | light on road signals can be located on the same |
| Well, here is the perfect answer to give them... | | | | signal apparatus as the red danger light. |
| Railroad signals serve a similar purpose to that of | | | | Trains, however, are heavy and take considerable |
| traffic signals for cars on roads. In fact; road | | | | time and distance to stop. The typical coal train |
| signals were developed from railway signals, not | | | | has 6 power units at 200 tons each and 115 cars |
| the other way around. | | | | at 120 tons each. The train weighs 15,000 tons. |
| When driving a car, the yellow/amber light | | | | Trains may require from half a mile, to a mile and |
| appears for a few seconds before the red light | | | | a half to come to a complete stop. |
| appears as a warning to prepare to stop (note: | | | | As an example; let us assume a train travels at |
| road traffic laws vary from country to country | | | | 55 mph and the car speed is 0 mph in the train |
| so the exact meaning of a yellow/amber signal | | | | direction of travel. By multiplying 55 x 15000, you |
| may vary depending on where you live). On a | | | | get 825,000. Then divide this by the weight of |
| road the yellow/amber signal could be timed | | | | the car and train combined. You get 54.9936 mph |
| depending on a number of factors such as the | | | | for the train after impact. |
| volume of traffic and/or prevailing speed on the | | | | This is why, trains need a warning signal well |
| road the signal governs. The timing of the yellow | | | | before the point where they have to stop. That |
| amber signal phasing is likely to take into account | | | | is one of the biggest differences between train |
| probable stopping distances for cars and trucks | | | | signals and road signals. |
| on the particular road. | | | | So, there you have the perfect answer to give |
| Unlike trains, cars and trucks do not take as much | | | | visitors when they ask why your trains run slow |
| time or distance to stop. A car weighs about | | | | when approaching signals on your model railway |
| 3,500 pounds or 1.75 tons. The other difference is | | | | layout. |
| that cars and trucks can change direction to avoid | | | | |