Reference

PCU values as per IRC:64-1990

The passenger car unit (PCU) value for each of the 19 vehicle classes in our classified volume counts: 18 take their factor from IRC:64-1990 Table 1, and Other is ours. These are the factors our software applies, published so you can check the arithmetic in any output we hand you.

Classes

18 categories plus an Other bucket.

IRC:64 edition

1990

Still current: IRC’s publications list of 28 September 2026 has no later edition.

PCU factors follow IRC:64-1990, Guidelines for Capacity of Roads in Rural Areas. Another schedule, such as IRC:106-1990 for urban roads, is set up on request where a client specifies one.

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.

Canonical classes with IRC:64-1990 passenger car unit factors

Canonical classes with IRC:64-1990 passenger car unit factors
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	1.5
TROL	Tractor Trolley	4.5
CYC	Cycle	0.5
RICK	Cycle Rickshaw	2.0
OTH	Other	1.0

Corrected 13 October 2026: Tractor was listed, and applied by our software, at 4.5, which is the factor Table 1 gives a tractor-trailer. A tractor alone is 1.5 (row 3). Releases made before that date still apply 4.5; for their outputs, recompute the Tractor row at 1.5.

The standard itself

IRC:64-1990 Table 1, as printed

IRC:64-1990 lists ten vehicle types. Our 18 named classes are finer, so each takes the factor of one row. Here is the table as the code prints it, with the classes that take each row, so the mapping can be checked.

Table 1 · Recommended PCU factors for various types of vehicles on rural roads

IRC:64-1990 Table 1, recommended PCU factors, with the classes that take each row
S. No.	Vehicle type, and our classes	Factor
Fast vehicles
1	Motor cycle or scooter2W	0.50
2	Passenger car, pick-up van or auto-rickshaw3W · CAR · assigned: MLCV	1.00
3	Agricultural tractor, light commercial vehicleLCV · TRAC · assigned: MBUS	1.50
4	Truck or busBUS · T2 · T3	3.00
5	Truck-trailer, agricultural tractor-trailerTROL · assigned: T4 · T5 · T6 · MAV · ARTIC	4.50
Slow vehicles
6	CycleCYC	0.50
7	Cycle-rickshawRICK	2.00
8	Hand cartno class of ours	3.00
9	Horse-drawn vehicleno class of ours	4.00
10	Bullock cart*no class of ours	8.00

* Table 1 footnote: “For smaller bullock-carts, a value of 6 will be appropriate.”

Table 1 has no row for a mini bus, a mini LCV, a multi-axle truck or a semi-trailer (articulated) combination; its row 5 names a truck-trailer. Those classes are marked assigned: they take the factor of the row they are listed under. Other is ours, at 1.0, for the reason given below.

The factors are “meant for open sections and should not be applied to road intersections” (clause 7.1). Clause 7.2 keeps the same factors on rolling and hilly sections, because terrain is already accounted for in the code’s design service volumes.

Source: IRC:64-1990, Guidelines for Capacity of Roads in Rural Areas (First Revision), Table 1, clauses 7.1–7.2 (public copy).

Urban roads

Urban roads have their own table: IRC:106-1990

IRC:64-1990 is written for rural roads. For urban roads in plain areas, IRC:106-1990 sets its own factors, and they move with the traffic mix: the code says “the relative PCU of a particular vehicle type will be affected to a certain extent by increase in its proportion in the total traffic”. Its Table 1 therefore gives each type one factor at 5% of the traffic stream and another at 10% and above. Clause 7 gives no rule for shares in between.

IRC:106-1990 Table 1 · Recommended PCU factors on urban roads

IRC:106-1990 Table 1, recommended PCU factors on urban roads, by the vehicle type’s share of the traffic stream
S. No.	Vehicle type	At 5%	10% and above
Fast vehicles
1	Two wheelers: motor cycle or scooter etc.	0.5	0.75
2	Passenger car, pick-up van	1.0	1.0
3	Auto-rickshaw	1.2	2.0
4	Light commercial vehicle	1.4	2.0
5	Truck or bus	2.2	3.7
6	Agricultural tractor trailer	4.0	5.0
Slow vehicles
7	Cycle	0.4	0.5
8	Cycle rickshaw	1.5	2.0
9	Tonga (horse-drawn vehicle)	1.5	2.0
10	Hand cart	2.0	3.0

The two codes can give the same vehicle different factors. Two-wheelers were 60% of traffic at the sites in our published validation; at that share a two-wheeler counts 0.50 in IRC:64-1990 and 0.75 in IRC:106-1990.

Our software applies the IRC:64-1990 factors set out above. This table is here so an urban count can be checked against the code written for it.

Source: IRC:106-1990, Guidelines for Capacity of Urban Roads in Plain Areas, Table 1 and clause 7.2 (public scan).

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 28%, and almost all of that comes from one class: two-wheelers were 60% 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.

Counted vehicles converted to PCU, 11 August 2026

Counted vehicles converted to PCU, 11 August 2026
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

There is no single class schedule

The classified count proforma in IRC:SP:19-2001 has columns for fifteen named classes plus Others, offered as a typical format that “may be used”; the 2020 revision is now the current edition. Our schedule has 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.

The schedule is wider than the current model, which has no class for articulated trucks or cycle rickshaws. Those two columns read zero, and such a vehicle is counted in another class or not at all.

Where a client’s schedule is coarser and its classes line up with ours, reporting to it is arithmetic: columns are added together. 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. That is our choice, not a Table 1 row: IRC:64-1990 has no factor for a vehicle that has not been classified.

Sources: IRC:SP:19-2001, clause 6.2 and Proforma 1 (public copy); Indian Roads Congress, List of IRC Publications as on 28-09-2026.

Check it on your own road

Send fifteen minutes and read the arithmetic

We will return the classified count, the PCU summary and the annotated video, so every figure above can be checked against the frame it came from.

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