Reference
Vehicle classes and PCU factors
The 19 classes an Indian classified volume count is reported against, and the passenger car unit factor each one carries. These are the factors our software applies, published so you can check the arithmetic in any output we hand you.
Classes
19
18 categories plus an Other bucket.
IRC SP:19 asks for
17
We carry more, never fewer.
The full schedule
Every class, and what it counts as
A passenger car unit converts a mixed-vehicle count into an equivalent number of cars, so capacity and level of service can be assessed on a single scale. A bus occupies road space three cars would; a two-wheeler occupies half of one.
| Code | Class | PCU factor |
|---|---|---|
| 2W | Two Wheeler | 0.5 |
| 3W | Three Wheeler | 1.0 |
| CAR | Car / Jeep / Van | 1.0 |
| MBUS | Mini Bus | 1.5 |
| BUS | Bus | 3.0 |
| MLCV | Mini LCV | 1.0 |
| LCV | LCV | 1.5 |
| T2 | Truck 2-Axle | 3.0 |
| T3 | Truck 3-Axle | 3.0 |
| T4 | Truck 4-Axle | 4.5 |
| T5 | Truck 5-Axle | 4.5 |
| T6 | Truck 6-Axle | 4.5 |
| MAV | Truck MAV | 4.5 |
| ARTIC | Truck Articulated | 4.5 |
| TRAC | Tractor | 4.5 |
| TROL | Tractor Trolley | 4.5 |
| CYC | Cycle | 0.5 |
| RICK | Cycle Rickshaw | 2.0 |
| OTH | Other | 1.0 |
Worked example
Why the PCU total is lower than the count
These are the six classes from our published validation that carried enough manual counts to be reported. Converting them shows the effect that makes PCU worth reporting at all.
15,487 vehicles convert to 11,187.5 PCU. The count falls by roughly a third, and almost all of that comes from one class: two-wheelers were 60% of all traffic of traffic at these sites, and each counts as half a car.
This is why a raw vehicle count and a PCU total are not interchangeable, and why a capacity assessment built on the wrong one is wrong by a wide margin on Indian arterials.
| Class | Counted | Factor | PCU |
|---|---|---|---|
| Car / Van / Jeep | 3,036 | 1.0 | 3,036 |
| 3-Wheeler | 2,633 | 1.0 | 2,633 |
| Bus | 161 | 3.0 | 483 |
| 2-Wheeler | 8,941 | 0.5 | 4,470.5 |
| Cycle | 302 | 0.5 | 151 |
| Mini LCV | 414 | 1.0 | 414 |
| Total | 15,487 | 11,187.5 |
Why nineteen
IRC SP:19 asks for seventeen
The standard schedule for a classified volume count names 17 classes. We carry 18 named categories plus an Other bucket, because a class we do not name is a class that silently lands somewhere it does not belong.
Reporting to a 17-class schedule from a 19-class detection is arithmetic. Going the other way is guesswork. Anything the model cannot place with confidence lands in Other and stays visible, rather than being distributed into the classes around it to make a total look tidy.
Other is counted at 1.0 PCU — a car equivalent — which is the conservative choice, since inflating unclassified traffic would flatter a capacity figure.
Check it on your own road
Send fifteen minutes and read the arithmetic
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