Disturbances Design
From this design we start implementing the following:
Blockages : Car, switch, derailment, defective tram.
Incidents : Woman in labour, angry mob
Track disturbances occur randomly in the game resulting in a tram track being blocked in a single location. At this instant, an ascending timer appears to indicate the elapsed time since the start, as an information for the player, also used for scoring purposes. It is to create a sense of urgency for the player and allow him to easily compare handling similar disturbances during gameplay. When a blockage appears the player needs to perform an action on it and possibly on the trams nearing it. If a tram is not stopped before the blockage by the player there is a small (5%) chance of it ramming the obstacle (or the tram ahead of it), resulting in penalty points. Otherwise it will stop on its own just before the obstacle. When an action on the blockage is performed, another, this time descending timer appears, indicating the time until the issue is resolved. However, some of the possible actions to perform have only a chance of success and take shorter time, other are certain but require more time. Moreover, the player is presented with other options, not suitable for this obstruction but still possible to choose from. In this case the timer also appears but when it has counted down, the blockage remains in place (similarly for right actions which were unsuccessful). There are no restrictions on how many times can a certain action be tried on the blockage. Whenever a player clicks on a blockage or a tram the game pauses until he chooses an action (or cancels). Trams can be stopped at any time and restarted as well, providing there is no blockage right ahead. When an issue is resolved, the trams will not proceed on their own, they need to receive a ‘go’ from the traffic controller (player). A desirable solution for blockage is rerouteing trams approaching the obstacle. Each of the trams needs to be rerouted manually and their paths can be different. Any affected by a blockage tram, should additionally be contacted to inform the passengers about the inconvenience. Providing information to unaffected trams yields penalty points due to confusion. Basic blockage structure:
A list of possible correct actions for different blockages is presented below.
- Car (movable object) on tracks
| Action | Probability of Success | Time Needed | Notes |
|---|---|---|---|
| Ask the tram driver to push the object aside | 25% | 10min | Works only with small objects. Requires a tram before the blockage |
| Use external horn repeatedly | 10% | 3min | Penalty points for passenger utility due to noise. Requires a tram before the blockage |
| Call towing service | 100% | 30min | Cost increase |
- Tree (stationery object) on tracks
| Action | Probability of Success | Time Needed | Notes |
|---|---|---|---|
| Ask the tram driver to push the object aside | 2% | 10min | Works only with small objects. Requires a tram before the blockage |
| Wait for municipality services to deal with the problem | 90% | 45min | Costless but uncertain |
| Call for crane service | 100% | 60min | Cost increase |
- Damaged power line
| Action | Probability of Success | Time Needed | Notes |
|---|---|---|---|
| Call for maintenance crew | 80% | 60min | |
| Provide towing | 100% | 30min | Permanent speed reduction |
- Defective tram (happens only to trams on the map or depots)
| Action | Probability of Success | Time Needed | Notes |
|---|---|---|---|
| Call for maintenance crew | 90% | 45min | |
| Tow it with another tram | 90% | 15min | Requires two trams. Slightly unrealistic |
| Call for towing | 100% | 45min |
- Collision (happens only to trams on the map)
| Action | Probability of Success | Time Needed | Notes |
|---|---|---|---|
| Call for emergency services | 100% | 90min | |
| Ask tram driver to request passage | 20% | 10min | Works only for minor collisions |
- Derailment (happens only to trams on the map)
| Action | Probability of Success | Time Needed | Notes |
|---|---|---|---|
| Call for crane service | 95% | 90min | |
| Call for emergency services | 100% | 120min | In case of casualties |
- Defective line switch
| Action | Probability of Success | Time Needed | Notes |
|---|---|---|---|
| Call for maintenance service | 100% | 45min | |
| Ask drivers to switch manually | 75% | 15min | Permanently reduce speed in the section. Requires a tram before the blockage |
- Traffic lights failure
| Action | Probability of Success | Time Needed | Notes |
|---|---|---|---|
| Call for maintenance service | 100% | 30min | |
| Ask drivers to proceed carefully | 100% | 5min | Permanently reduce speed in the section. Requires a tram before the blockage |
| Ask for police assistance in traffic management | 50% | 20min |
- Driver unavailable (only in depot)
| Action | Probability of Success | Time Needed | Notes |
|---|---|---|---|
| Call for additional driver | 80% | 30min | Extra cost |
| Cancel tram | 100% | 10min | Resulting in points penalty |
If the next tram does not stop before the blockage and rams into it, the situation escalates. Next to significant penalty points there are other consequences listed below:
| Blockage | Primary Result (chance) | Secondary Result (chance) | Notes |
|---|---|---|---|
| Car (movable object) on tracks | Derailment (50%) | Collision (50%) | Depending on severity |
| Tree (stationery object) on tracks | Derailment (70%) | Collision (30%) | Depending on severity |
| Damaged power line | Derailment (75%) | Defective tram (25%) | |
| Defective tram | Derailment (90%) | Collision(10%) | |
| Collision | Derailment (90%) | Collision (10%) | |
| Derailment | Derailment (90%) | Collision (10%) | |
| Defective line switch | Derailment (100%) | - | |
| Traffic lights failure | Collision (50%) | No consequences (50%) |
Note that tram ramming another tram in front of it is always treated as tram running into a defective tram and it is not possible to ram into a tram in a depot.
Tramcar incidents are limited only to the trams and are introduced to increase the variety in the game, so that the players do not continue to face the same problems all the time. They are, nevertheless, of lower importance than the blockages. Incidents occur randomly throughout the game and need to be dealt with as soon as possible. If a correct action is chosen by the player, it is awarded by extra points. If an wrong action is chosen, the player can repeat his choice after 5min without a direct penalty. However, if the situation is not resolved after an hour, it may escalate into a bigger problem. Yet, if it is solved before that, there is no impact on tram operations and the player is awarded with extra points.
Below, a set of possible tramcar incidents is shown, along with correct advices of the traffic controller to deal with the problem are shown:
- Drunken passenger
| Action | Notes |
|---|---|
| Stop the tram and ask to leave | One needs to restart the tram manually |
- Angry mob
| Action | Notes |
|---|---|
| Call the police |
- Woman in labour
| Action | Notes |
|---|---|
| Call an ambulance |
- Passengers in distress
| Action | Notes |
|---|---|
| Calm them down |
- Fire on board
| Action | Notes |
|---|---|
| Extinguish it with a hand extinguisher |
- Air-gun firing at tram
| Action | Notes |
|---|---|
| Call the police |
- Stench on board
| Action | Notes |
|---|---|
| Ventilate the tram |
If the right action is not performed and the one hour limit reached the situation has always 50% chances of escalating into something serious. On top of that, there is always a score penalty for not dealing with the issue. Below, a table of possible consequences of not solving certain tramcar issues is shown. It is not limited to tramcar incidents but also includes blockages.
| Incident | Primary Result (chance) | Secondary Result (chance) | Notes |
|---|---|---|---|
| Drunken passenger | Passengers in distress (70%) | Angry mob (30%) | |
| Angry mob | Passengers in distress (40%) | Defective tram (60%) | Depending on severity |
| Woman in labour | Passengers in distress (100%) | - | |
| Passengers in distress | Angry mob (100%) | Repeating cycle of losing points | |
| Fire on board | Passengers in distress (50%) | Defective tram (50%) | |
| Air-gun firing at tram | Passengers in distress (90%) | Angry mob (10%) | |
| Stench on board | Passengers in distress (70%) | Angry mob (30%) |
It should be noted, that the “Angry mob” incident is considered most severe and not dealing with it is punished with the highest point penalty.
At any given point in the game the player is able to change the route of a single tram. If multiple tram paths are to be altered, the player needs to do this manually for each of them. There are no predetermined consequences of altering tram paths. Tram stops, however, need to be visited every given fixed period of time. Regular setting without disturbances has predefined tram routes that fulfil that requirement but altering routes can complicate that. The player needs to make sure that all stops are visited within that given time and if not, he is will start losing point for every real-time second when the stop is not visited after the period from last visited tram has passed.
Informing travellers of possible delays or difficulties is a vital part of every traffic controller’s job. After all, it is all about the passengers. Thus, in case of a blockage and rerouteing the player needs to choose affected stations and perform “Inform passengers” action that is the same for all blockages. The challenge is to only perform this action on affected stations, since choosing wrong one results in travellers’ utility score penalty, bigger than the added points for selecting the right one.