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Here you can find information about how OpenTTD calculates in-game figures.

You always wanted to know how the station-rating was built up? How goods-distribution works? Here you can find it!

Contents

Company rating

Each part of the company rating is a linear function, i.e. earning 50% of the target for a component will give 50% of the points allocated for that component. Where components involve monetary amounts, these are converted to the currency of the current game; internally these amounts are stored as the pound amount.

Component Target Points (min) Points (max) Percentage
Number of company-owned vehicles that turned profit last year >=120 0 points for 0 vehicles 100 points for at least 120 vehicles 0 to 10%
Number of recently-served station parts that the company owns >=80 0 points for 0 parts 100 points for at least 80 parts 0 to 10%
Lowest profit of vehicles at least two years old >=£10,000 0 points for loss or £0 100 points for at least £10,000 0 to 10%
Lowest quarterly revenue earned in the past 3 years >=£50k 0 points for £0 50 points for at least £50k 0 to 5%
Highest quarterly revenue earned in the past 3 years >=£100k 0 points for £0 100 points for at least £100k 0 to 10%
Units of cargo delivered in the past year >=40,000 0 points for 0 units 400 points for at least 40,000 units 0 to 40%
Number of types of cargo delivered in the past quarter >=8 0 points for 0 cargo-types 50 points for at least 8 cargo-types 0 to 5%
Current cash in bank >=£10m 0 points for £0 50 points for at least £10m 0 to 5%
Current loan from bank £0 0 points for >£250k 50 points for £0 0 to 5%
Totals

0 points 1000 points 0 to 100%
Company League Table ratings
Rating Title
0 to 127 Engineer
128 to 255 Traffic Manager
256 to 383 Transport Coordinator
384 to 511 Route Supervisor
512 to 639 Director
640 to 767 Chief Executive
768 to 895 Chairman
896 to 959 President
960 to 1000 Tycoon
2050 High Score ratings
Rating Title
0 to 319 Businessman
320 to 447 Entrepreneur
448 to 575 Industrialist
576 to 703 Capitalist
704 to 831 Magnate
832 to 959 Mogul
960 to 1000 Tycoon of the Century

Station rating

This section shows the factors that affect the station rating. All calculations are done separately for each cargo type.

Factor Condition Rating points Rating %
Max speed of last vehicle to load cargo (to a max of 255 km/h)
Divide speed by 2 if it was a road vehicle.
Above 85 km/h (52 mph) (Speed (km/h) - 85) / 4 0% to 17%
Age in years of last vehicle to load cargo 2 10 4%
1 20 8%
0 33 13%
Days since last cargo pickup
Multiply days in "Condition" column by 4 if last vehicle was a ship.
(Note: If a vehicle was ready to pick up a cargo but there was no cargo, or if it was full, it is still regarded as a cargo pickup. This may be a bug.)
30 to 52.5 25 10%
15 to 30 50 20%
7.5 to 15 95 37%
less than 7.5 130 51%
Units of cargo waiting at station
Note: if cargo has been transferred to other stations, then the game MAY consider the maximum cargo waiting at any of those stations as the waiting cargo for the source station: TruncateCargo(). This is triggered when the game truncates cargo (waiting_changed = true), which occurs when any of the stations meet the following conditions:
  • Cargo has not been picked up from any of those stations in 637.5 days. [1]
  • Station has rating less than or equal to 25% AND has more than 200 units of cargo waiting. [2]
  • Station has rating less than 50% AND has more than 0 units of cargo waiting, happening with RANDOM PROBABILITY proportional to the station rating. I.E. if station rating is 49%, there is a ~1% chance, at 25% rating there is a ~50% chance, and at 0% station rating there is a 100% chance. [3]
  • Station has more than 4096 units of cargo waiting. [4].
More than 1500 -90 -35%
1001 to 1500 -35 -14%
601 to 1000 0 0%
301 to 600 10 4%
101 to 300 30 12%
less than 100 40 16%
Statue in town of station Built 26 10%
Event Condition Rating point change Rating % change
Small advertising campaign bought Station within 10 tiles of town center +64 +25pp
Medium advertising campaign bought Station within 15 tiles of town center +112 +44pp
Large advertising campaign bought Station within 20 tiles of town center +160 +63pp
Road vehicle crashed Station within 22 tiles of crash -160 -63pp
Train crashed Station within 30 tiles of crash -160 -63pp
Town bribe failed Station within town influence -255 -100pp

Divide the total rating points by 255 to get the percent rating. The maximum possible rating is 100%.

Every 2.5 days (185 ticks), station ratings are computed; ratings can't change by more than 2 points (0.78%) per cycle, except due to items under "Event". Events give an instant, temporary boost (or penalty) to ratings of nearby stations. The rating will gradually return to normal, following the 2 point per 2.5 days rule.

The amount of cargo that can be transported from an industry is fully reliant on the station rating. This means that if there is exactly one station serving an industry, on ticks when the industry produces cargo, exactly station rating % of the cargo will be moved to the station. So if the amount of cargo transported from an industry is low, it is probably because the station rating is low, too.

Note: The exact formula can be seen under "UpdateStationRating()" in station_cmd.cpp. This uses some values calculated in "LoadUnloadVehicle()" in economy.cpp.

Note: If the rating gets to be less than 50%, the station starts losing cargo.

Note: If the amount of cargo waiting is greater than 4096 units (or 4,096,000 liters), the station also starts losing cargo. There is a hard cap of 32,768 units of cargo that can be waiting at a station. Any more than that completely disappears every few days. [5]

Cargo delivery to stations

Goods are distributed to stations according to station rating.

If there is only only station around, then a percentage of available goods equal to the station's rating is distributed to it every 2.5 day cycle.

If multiple stations are present, then goods are divided between them based on rating. If there are stations belonging to more than one company, then goods are first divided between companies according to the best station of each company: the proportion of goods allocated to a company C is equal to the best station rating of C over the sum of all best station ratings for all companies. Note that this will be equal to 100% if all stations belong to one company. Then each company's allocation is subdivided among its stations. A station S belonging to C receives a fraction of C's company allocation equal to the rating of S over the sum of the ratings of all stations belonging to C.

Local authority rating

Ratings limit some player actions; they start at +500 and can change based on some actions.

Currently you can exploit the game by planting about 200 trees within a town's influence radius. You may need to clear an area first, in order to have somewhere to plant them, but planting 200 will raise even a minimum rating of -1000 to 220. If your rating is Mediocre or lower, planting 30 trees will approximately wipe out the rating penalty from building one station. Planting trees while at a rating of Very Good or better has no effect.

Rating points Rating
-1000 to -400 Atrocious
-399 to -200 Very Poor
-199 to 0 Poor
0 to 200 Mediocre
201 to 400 Good
401 to 600 Very Good
601 to 800 Excellent
801 to 1000 Outstanding
Player action Required rating* Effect on rating
Build a station -200 n/a
Destroy an 'edge' piece of road 16 / 64 / 112 -18, down to -100.
Destroy an 'inner' piece of road 16 / 64 / 112 -50, down to -100.
Destroy a city tunnel or bridge 144 / 208 / 400 -250, down to 0.
Destroy building** 40 to 300 -40 to -300
Plant tree on clear square n/a +7, up to 220.
Clear a tile with trees n/a -35
Successful bribe n/a +200, up to 800.
Unsuccessful bribe n/a Set to -50.
* "Required rating" is listed for the settings Permissive / Neutral / Hostile of
the Difficulty option City council attitude towards area restructuring.
** For default buildings. NewGRFs can set this number from 0 to >1000,
which effectively makes the building unremovable.

Each month players' ratings automatically change:

Example:
A player has a rating of -300, (Very Poor), 2 active stations and 1 inactive station at a town.
5pts + 2 * 12pts - 15pts = 14pts points gain per month.
(-200 - -300)pts / 14pts/mo = 8 months before the town will let him build another station.

Code for town ratings is in town.h, town_cmd.c, tree_cmd.c, and road_cmd.c.

Passenger and Mail generation

Towns and the company headquarters generate passengers and mail, while oil rigs only generate passengers.

Town Passenger Generation

In each periodic processing (i.e. every 256 ticks), a random value 0<=X<=255 is generated for each house tile. If X isn't smaller than the population of the tile, no passengers are generated. Otherwise, X/8+1 passengers are generated (rounded down). If there is a recession going on, the number of generated passengers is halved, but this division gets rounded up instead of down. Mail generation happens in a similar manner, but with a new random value, and checking against the mail generation multiplier instead of the population. See the full list of default values for HouseProps: [6]

Company Headquarters

The Company Headquarters is a unique structure that generates passengers and mail depending on it's level which is dependent on the performance rating of the company. Higher level company HQs generate more passengers and mail, the output of the headquarters is evenly distributed over all four tiles on a per tile basis as per the following formulas:

Passengers: 256 / 4 tiles / (6 - company HQ Level (a value between 1 and 5) )

Mail: 196 / 4 tiles / (6 - company HQ Level (a value between 1 and 5) )

Industry production

Here is how the game determines how much cargo an industry produces per month. Production of raw materials happens 8 or 9 times per month. (It happens every 256 ticks. There are 74 ticks in a day, and 28 to 31 days in a month (date_type.h). This means that only about 9% of industries will produce 9 times in a 28-day February, but about 96% of industries will produce 9 times in a 31-day month like March.) The production will always be a multiple of 8 or 9, unless the industry changed production during that month.

This table lists possible starting productions governed by the smooth economy patch. These numbers are multiples of 8. When the game generates a new map, each industry produced 8 times and had no production changes in the December before the game started.

Raw Material Industry Produced Cargo Initial production range
Coal Mine Coal 56 to 176
Forest Wood 48 to 152
Oil Rig Oil 56 to 176
Farm Grain and Livestock 40 to 112
Copper Ore Mine Copper Ore 56 to 112
Oil Wells Oil 48 to 152
Iron Ore Mine Iron Ore 40 to 112
Bank (temperate) Valuables 24 to 64

Gold Mine Gold 24 to 80

Diamond Mine Diamonds 24 to 80
Fruit Plantation Fruit 40 to 112
Rubber Plantation Rubber 40 to 112
Water Supply Water 48 to 152
Farm Maize 40 to 128
Lumber Mill Wood 180 or 225 (if trees available)

Candyfloss Forest Cotton Candy 48 to 152
Battery Farm Batteries 40 to 128
Cola Wells Cola 48 to 136
Plastic Fountains Plastic 56 to 160
Bubble Generator Bubbles 48 to 152
Toffee Quarry Toffee 40 to 112
Sugar Mine Sugar 40 to 128

(To calculate this table, look under _origin_industry_specs in table/build_industry.h for the industry and its cargo. The sugar mine has CT_SUGAR, 11, so the production starts at 11. Apply the formula from DoCreateNewIndustry() in industry_cmd.cpp: multiply the production by a random integer from 128 to 383, then divide by 256, rounding down. So 11 becomes 5 to 16. Finally, multiply it by 8 to get 40 to 128.)

Production change

Each month the game randomly changes some industry productions.

Default / TTD-like Economy Rules

For 256x256 tile maps there is one change per month possible (only 1 industry changes). Number scales nicely with map size since the introduction of "Daily production changes" function in trunk (r14332).

However - productions are limited to 6 production levels: lowest, lower, normal (with a new game started or a new industry built), higher, 2x higher and the highest. Production changes between these levels are either a 50% decrease (half) or a 100% increase (double).

To make things simple, let's look what are the chances for 256x256 maps (max. 1 change per month = max. 1 industry per month changes production):

Smooth Economy Rules

/File/en/Outdated content.png
Out of Date
This article or section is outdated. Some of its content may no longer be accurate due to changes in the latest release. Please update this article.
Difficulty setting and Advanced setting have been replaced by Settings
Distinguish Smooth economy (advanced setting) and Steady economy (difficulty setting)
Special Cases

Examples

If a coal mine has 70% of its output transported, there is a 3% chance (4.5% * 67%) of a production increase from 3-23% and a 1.5% chance (4.5% * 33%) of a production decrease from 3-23% (but 13% on average).

(1 + (0.03 - 0.015) * 0.13) ^ 12 - 1 = 0.0237 or 2.37%

The coal mine will grow an average of 2.37% on average after the first year.
(1.0237 ^ 20) - 1 = 59.6% after twenty years
(1.0237 ^ 50) - 1 = 321.8% or 3.22x after fifty years
(1.0237 ^ 100) - 1 = 10.35x after one hundred years

For an industry with rating of more than 80%, there is a 3.75% chance of increase and 0.75% chance of decrease:
(1 + (0.0375 - 0.0075) * 0.13) ^ 12 - 1 = 0.0478 or 4.78%

The industry will grow approximately 4.78% on average after the first year.
(1.0478 ^ 20) - 1 = 2.54x after twenty years
(1.0478 ^ 50) - 1 = 10.32x after fifty years
(1.0478 ^ 100) - 1 = 106.62x after one hundred years

For an industry with the only_decrease flag set (currently Temperate Oil Wells), there is only a 4.5% chance of decrease:
(1 + (0 - 0.045) * 0.13) ^ 12 - 1 = (0.99415) ^ 12 -1 = -0.068 or -6.8%

The industry will shrink on average by approximately 6.8% after the first year.
(0.9320 ^ 20) = 24.46% of initial production after twenty years
(0.9320 ^ 50) = 2.96% of initial production after fifty years

ln(0.5) / ln(0.99415) = 118.1 months or 9.84 years is the half life of an only_decrease industry.
ln(8 / 48) / ln(0.99415) = 305.9 months or 25.4 years is the mean lifetime of a temperate Oil Wells (starting at 48 oil/month).
ln(8 / 152) / ln(0.99415) = 501.8 months or 41.8 years is the mean lifetime of a temperate Oil Wells (starting at 152 oil/month).

For good service, it takes 29.6 years on average to double; with excellent service, it takes 14.8 years. If in the game's time a day is 2.36 seconds, then the doubling time with good service is 7.1 hours; with excellent service, the doubling time is 3.6 hours. For production to go from near bottom of 100 to near maximum of 2040 or 2295 takes 130 years with good service and 65 years with excellent service.

However, in game you will find industries changing their production rate very randomly. It must be stressed the above examples are only true when observing many industries over the long-term; individual industries may greatly deviate from these averages. Statistically speaking, 6 out of 10 industries will not go from 100 to 2040-2295 even with the best service during 65 years. About 1 out of 9 industries will even lower their production when being served at 60-80% cargo transported for 50 years.

For more responsiveness from industries, adapt the number of wagons to industry production (for the lowest production, you should use two wagons). [Full Load] orders are usually used for such cargo trains.

Note: The exact formula can be seen under "ChangeIndustryProduction()" in industry_cmd.cpp.

Delivery payment rates

The amount you get paid for delivering cargo is based on 4 factors: the amount of cargo you deliver, the value of the cargo, the distance you deliver it, and how on-time you deliver it.

Cargo Units Early Delivery
Time (days)
Late Delivery
Time (days)
Initial cargo
payment (pounds)
Passengers

Immediate 24 £39
Valuables Bags 1 32 £91
Livestock Items 4 18 £53
Grain Tons 4 40 £58
Goods Crates 5 28 £75
Coal Tons 7 None £72
Steel Tons 7 None £69
Iron Ore Tons 9 None £62
Wood Tons 15 None £61
Oil Kiloliters 25 None £54
Mail Bags 20 90 £55
Arctic specific
Wheat Tons 4 40 £58
Paper Tons 7 60 £66
Gold Bags 10 40 £71
Food Tons Immediate 30 £69
Tropical specific
Rubber Kiloliters 2 20 £54
Fruit Tons Immediate 15 £51
Maize Tons 4 40 £53
Tropical Wood Tons 15 None £97
Copper Ore Tons 12 None £59
Water Kiloliters 20 80 £57
Diamonds Bags 10 None £71
Toyland specific
Sugar Tons 20 None £54
Toys

25 None £68
Batteries

2 30 £53
Sweets Tons 8 40 £75
Toffee Tons 14 60 £58
Cola Kiloliters 5 75 £59
Candyfloss Tons 10 25 £61
Bubbles

20 80 £62
Plastic Kiloliters 30 None £54
Fizzy Drinks

30 50 £76

Initial cargo payment values are for delivering 100 pieces of cargo 1 tile. Payment goes up with inflation as the game progresses.

Late delivery penalties:

Examples (no inflation):
Deliver 200,000 liters of oil 20 squares in 10 days:
2 * £54 * 20 squares * 100% = £2160

Deliver 100 bags of mail 100 squares in 100 days:
£55 * 100 squares * (1 - 0.80*0.4 - 0.10*0.4) = £3520

HINT calculate easy:
Income = cargo units * cargo value * 0.4
Cargo value comes from the Y-axis on the specific transported goods graph in-game
measure your real delivery time in days and plot on x-axis This result will give you an easy estimation of your income with 5% deviation

Notes:

Vehicle speeds

Internally OpenTTD works with a unit called "km-ish/h", which is equal to "mph*1.6". The conversion factor from km-ish/h to km/h is 1.00584, and the conversion factor from km-ish/h to mph is 1.6.

A tile is, for vehicle speed purposes 664.(216) km-ish, 668 km or 415 miles long. This is based on the following facts:

Now assume a vehicle going 1 km-ish/hour: (1 * 16 * 256) / (74 * 2) * 24 = 664.(216).

The net result is that 100 km/hour is ~3.6 tiles/day.

Aircraft

Road Vehicles

(Note: This does not apply when using the improved road vehicle acceleration model.)

Ships

Trains

(with the realistic train acceleration patch)

Curvature Max speed (km/h)
Railroad Monorail Maglev
0 (90° turn) 61 91 121
1 (2x45° turn) 88 132 176
2 111 166 221
3 132 198 264
4 151 226 301
5 168 252 336
6 183 274 365
7 196 294 392
8 207 310 413
9 216 324 432
10 223 334 445
11 228 342 456
12+ 231 346 461
Curvature Max speed (mph)
Railroad Monorail Maglev
0 37 56 75
1 54 82 109
2 68 103 137
3 82 123 164
4 93 140 187
5 104 156 208
6 113 170 226
7 121 182 243
8 128 192 256
9 134 201 268
10 138 207 276
11 141 212 283
12+ 143 214 286

"Curvature" means the average number of wagons of the train between turns. However, very sharp turns (curvatures 0 and 1) are not averaged out in longer trains.

/File/en/Manual/Game Mechanics/Speed-limits.png

See also: Realistic acceleration and Corners.

See ground_vehicle.cpp, aircraft_cmd.cpp, roadveh_cmd.cpp, ship_cmd.cpp, train_cmd.cpp, vechicle.cpp for code.

As of OpenTTD 1.6.1, given power in hp, max tractive effort in kN, total weight of the train in tonnes, the number train parts (engines and wagons), the air drag value of the first engine in the train (NewGRF setting, defaults to min(192,max(1,floor(2048/max_speed))), meaning faster trains are built more aerodynamically), the combined weight of any train parts (engines or wagons) currently on an up-slope, the combined weight of any train parts (engines or wagons) currently on a down-slope, the slope steepness (game setting [1-10], default 3), and the current speed of the train in km/h, the acceleration of a non-maglev train can be calculated as follows:

force = min((max_te * 1000), floor((power * 746) / (current_speed * 5/18))) [N]

slope_force = weight_on_upslope * slope_steepness * 100 - weight_on_downslope * slope_steepness * 100 [N]

axle_friction = total_weight * 10 [N]

rolling_friction = floor((current_speed + 512) * 15 / 512) * total_weight [N]

air_drag_coefficient = 14 * floor(air_drag_value * (1 + number_of_parts * 3/20)) / 1000

air_drag = floor(air_drag_coefficient * current_speed^2) [N]

acceleration = (force - (slope_force + axle_friction + rolling_friction + air_drag)) / (total_weight * 4) [256th of a km/h per half-tick]

Note: air_drag_coefficient is twice that if any part of the train is in a tunnel.

Given the same values, the equilibrium speed, e.g. the speed the train would eventually settle on if the same conditions continued indefinitely, can be calculated as follows [Assuming a constant rolling_friction (i.e. the speed stays below 512 km/h), and ignoring the flooring of force and air_drag to an integer value]:

p = (slope_force + axle_friction + rolling_friction) / air_drag_coefficient

q = (-power * 746 * 18/5) / air_drag_coefficient

C = (27/2*q + ((27/2*q)^2 + 27*p^3)^(1/2))^(1/3)

equilibrium = min(max_speed, p/C - C/3, max(0, max_te * 1000 / air_drag_coefficient - p)^(1/2))

Town growth

See Towns#town-growth.