TfNSW Category 4 school bus: what the specification requires

Category 4 is a seat count, not a size. Under the Rural and Regional Bus Service Contract it means 44 authorised adult seats or more, excluding the driver — which in practice is a 12 metre bus. The vehicle requirements come from the BP4 specification, a procurement document rather than a sales brochure, so here is what it actually asks for.

What Category 4 means

Requirement	What it says	Source
Category definition	Under the Rural and Regional Bus Service Contract, a bus category is set by authorised adult seating capacity excluding the driver. Category 4 is 44 seats and above.	RRBSC cl. 1.1
Vehicle definition	A one-door, seatbelted, two-axle, single-deck bus with more than 43 seats excluding the driver, on dedicated school services under a Rural and Regional contract.	BP4 cl. 1.31
How a new bus is categorised	TfNSW determines the category for a new bus, weighing the operator’s actual patronage and projected peak passenger numbers against the seating capacities in the category table, with maximum passenger load measured under reg. 94 of the Passenger Transport Regulation 2007 (NSW).	RRBSC cl. 5.4(m)
Who the specification binds	Suppliers under the TfNSW Deed of Standing Offer, Bus Procurement Panel 4, and the bus operators contracted to TfNSW who own the buses.	BP4 cl. 1.5, 1.11
Maximum age	A contract bus must be replaced when it reaches the maximum age set in Paragraph 2 of the Contract Buses and Contract Depots Schedule, counted from the purchase date. Categories 1 and 2 run to 15 years; Categories 3 and 4 run to 25. At that point the bus comes off the contract and is replaced through the TfNSW Bus Procurement Panel.	RRBSC cl. 13.2(a)(i)
Depreciation	Depreciation under the contract is a separate clock from maximum age, and the two do not line up. Categories 1 and 2 depreciate at 7.69% a year, which writes the bus down over thirteen years against a fifteen year maximum age. Categories 3 and 4 depreciate at 5.00% a year, twenty years against a twenty-five year maximum age. So a contract bus is fully written down well before it has to come off the contract, which is what matters when you are working out a Vehicle Termination Payment.	RRBSC Payment Schedule para. 4.6
Depreciation	Depreciation under the contract is a separate clock from maximum age, and the two do not line up. Categories 1 and 2 depreciate at 7.69% a year, which writes the bus down over thirteen years against a fifteen year maximum age. Categories 3 and 4 depreciate at 5.00% a year, twenty years against a twenty-five year maximum age. So a contract bus is fully written down well before it has to come off the contract, which is what matters when you are working out a Vehicle Termination Payment.	RRBSC Payment Schedule para. 4.6

Seating and capacity

Requirement	What it says	Source
Seated capacity	Calculated at 65 kg per passenger, excluding the driver.	cl. 5.15, ADR 58/00
Standing capacity	Also at 65 kg per passenger, no more than 6.25 passengers per square metre of floor area, with the standing area sloping no more than 8%.	ADR 58/00
2-for-3 seating	Centre seats in a 2-for-3 arrangement are for children under 12 only, and must carry a warning label.	cl. 26.16
Seatbelts	Forward-facing retractable lap/sash belts with a current CRN and occupant-limit signage. 2-for-3 seats must also meet ADR 3/04 for energy dissipation and ADR 4/05 and 5/05 for belts and anchorages.	cl. 26.15, ADR 68/00
Child restraints	Six seat positions must have child restraint fittings.	ADR 68/00 cl. 5.6, ADR 34/03
Priority seating	At least four priority seats in the low-floor area near the accessible entrance, plus the wheelchair-area seats.

Dimensions

Requirement	What it says	Source
Maximum width	2,500 mm excluding mirrors.	cl. 6.2, ADR 43/04
Turning circle	25,000 mm wall to wall maximum; 24,300 mm preferred.	cl. 6.4, ADR 43/04
Ground clearance	Wheelbase in metres multiplied by 33.33 mm, measured mid-axle.	cl. 6.5
Rear overhang	3,700 mm maximum, or 60% of the wheelbase.	cl. 6.7
Door step height	380 mm maximum at normal suspension height; 320 mm maximum kneeling.	cl. 6.11–6.12
Headroom	1,800 mm minimum in the aisle; 1,650 mm minimum at the rear five-seat step.	cl. 6.13, 6.15
Seat to overhead	950 mm minimum.	cl. 6.16
Aisle width	380 mm minimum.	cl. 6.17

Engine, emissions and performance

Requirement	What it says	Source
Emissions	Euro 6 minimum. The specification notes that ADR 80/03 still only requires Euro 5, and that TfNSW requires Euro 6 regardless.	cl. 9.2
Fuel	Australian automotive diesel at 10 mg/kg sulfur.	cl. 1.12
Power	150–180 kW (200–250 hp) or 210–245 kW (280–330 hp).	cl. 5.18
Torque	750, 1,200 or 1,600 Nm minimum at around 1,200 rpm.	cl. 5.19
Acceleration, laden, air conditioning running	0–20 km/h in 5.0 s, 0–50 km/h in 15.0 s, 0–60 km/h in 19.0 s, 0–80 km/h in 27.0 s, tested on level or positively graded asphalt or concrete.	cl. 5.3
Top gear	Must reach 100 km/h.	cl. 5.5
Gradient	Must hold on an 18% grade, uphill and downhill, fully laden, without rolling back.	cl. 5.4
Range	A minimum 18 hours a day and up to 450 km without refuelling, with the air conditioning on.	cl. 4.4.1
Noise	Below 70 dB(A) at idle and 80 dB(A) at full throttle at the rear five seats, with Leq over an hour not above 72 dB(A).	cl. 5.9

Accessibility

Requirement	What it says	Source
Standard	Compliance with the Disability Standards for Accessible Public Transport 2002.	cl. 10.1
Wheelchair spaces	Two, each a minimum 1,300 × 800 mm with 1,500 mm clear height, to AS 1428.2.	cl. 9.2–9.3
Floor	Level within 1:30 in the wheelchair spaces.	cl. 10.2
Ramp	Manual ramp at the front door to AS 3856.1 and AS 3856.2 Type E, operable at no more than 100 N.
Restraint	Passive restraint and tether to TS148 and ADR 4/05.	cl. 10.10–10.11
Hearing augmentation	Loop to AS 1428.2 with full coverage, and a 110 × 100 mm decal on the entry door.	cl. 10.12
Steps	Riser 250 mm maximum; tread 275 mm minimum including a 25 mm undercut.
Door marking	Two 25 mm vertical yellow strips on the front door.

Doors

Requirement	What it says	Source
Front door	Wheelchair and ambulant entry and exit. Clear width 850 mm or 920 mm minimum depending on the option taken.	cl. 20.8.1–20.8.2
Centre or rear door	Ambulant exit, inward-glide double door, 920 mm minimum clear width.
Door safety	TS160: pre-set speed 5 km/h, door brake retardation 0.15–0.25 g, retardation tested on a 12° (18%) gradient.
Driver controls	On the driver’s right, with LED indicators — red for fault, green for OK, amber for override. Override cannot activate unless the handbrake is applied.	cl. 20.19
Emergency release	Buttons inside and outside, red internally at each door.
Compliance	Passenger doors to ADR 58/00, TS160 and TS147 (field of view of the passenger entrance doors of a bus).
Interior padding	TS148 covers padding for seat backs, handrails and partitions; the passive restraint and tether also reference it.	cl. 10.10–10.11

Signage, lights and destination

Requirement	What it says	Source
School bus signs and lights	To TS150.	cl. 30.2.10
End of shift child check	At the end of a shift the driver must check the bus. TfNSW puts it plainly: “Drivers do have a responsibility to ensure all students have safely exited the bus before end of shift.” Operators generally meet this with a child check system that sounds an alarm when the ignition is switched off and is only silenced by a button at the back of the bus, so the driver has to walk the aisle. We have not found a TfNSW document that mandates a particular device, so treat the duty as the requirement and the device as the usual way of discharging it.	TfNSW school bus FAQs
Bus stopping sign	Illuminates at the front when any stop button is pressed, and stays lit until the door opens.
Driver-side signage	Authority holder, “do not speak to driver”, bus number and the bus stopping sign.	cl. 31.17
Lamps	High-mounted front and rear direction indicators and stop lamps, and daytime running lamps to ADR 76/00.
Seatbelt sign	Illuminated “FASTEN SEATBELTS” sign, and an aisle grab handle on every second seat.
Destination	White-on-black LED indicators front, left side and rear. Glazing over external destination signs must be separate from other glass, untinted, and pass at least 75% of light.	cl. 21.13

Luggage

Requirement	What it says	Source
Bins	Per chassis configuration, typically two per side, each individually lockable and limited on the offside where traffic is a risk.	cl. 27.1
Rack	Optional extra.

All four categories

A bus category in New South Wales is a seat count, not a length. These are the bands from the Bus Category table at clause 1.1 of the Rural and Regional Bus Service Contract, which reads the same in the Small and Medium contracts.

Category	Adult seats, excl. driver	Maximum age	Depreciation	Ours in that band
Category 1	8 to 14	15 years	7.69% p.a.	—
Category 2	15 to 28	15 years	7.69% p.a.	ZBus L7 Diesel, 18 to 26
Category 3	29 to 43	25 years	5.00% p.a.	ZBus L8 Hybrid, 29
Category 4	44 and above	25 years	5.00% p.a.	ZBus H12 Diesel and H12 Hybrid, 57

TfNSW publishes nine BP4 vehicle specifications — Two Door City Bus Diesel (A), One Door Urban Diesel Bus (B), Category 4 Diesel School Bus (D), 14.5 metre Diesel Bus (E), Double Deck Diesel Bus (F), Category 4 Zero Emission School Bus (J), 14.5 metre Zero Emission Bus (K), Double Deck Zero Emission Bus (L), Articulated Deck Zero Emission Bus (M). Two are school buses and both are Category 4. Categories 1, 2 and 3 have no published vehicle specification at all.

Maximum age runs from the purchase date and is set in Paragraph 2 of the Contract Buses and Contract Depots Schedule. Depreciation is a different clock: at 7.69% a bus is written down over thirteen years against a fifteen year maximum age, and at 5.00% over twenty against twenty-five. Check both against your own contract. Seat counts are ours, from the specification sheets, and TfNSW determines the category for a new bus on patronage rather than on the brochure.

Everything the specification cites

Australian Design Rules: 1/00, 3/04, 4/05, 5/05, 6/00, 8/01, 13/00, 14/02, 34/03, 42/05, 43/04, 44/02, 46/00, 47/00, 48/00, 49/00, 58/00, 68/00, 74/00, 76/00, 77/00, 80/03, 86/00, 92/00, 93/00
NSW technical specifications: TS147 (mirrors and field of view), TS148 (padding and handrail retardation), TS150 (school bus signs and lights), TS160 (door safety)
Australian Standards: AS 1428.1, AS 1428.2, AS 3856.1, AS 3856.2, AS 5062, AS 2444, AS 1288, AS 3786

The source documents

Diesel Euro 6 — Category 4 School Bus, BP#4 specification v4.8 (15 March 2024)
TS142 / TS150 new bus technical specifications factsheet
Technical specifications application table (TS146, TS155, TS160)
Rural & Regional Bus Service Contract (Medium), March 2022 — the Bus Category table is at clause 1.1
NSW vehicle standards: technical specifications for buses
TfNSW school bus FAQs for parents, carers and students
TfNSW Bus Procurement Panel
TfNSW documents and forms for bus operators

Written 21 October 2026 from the documents linked above. TfNSW revises these; check the current version before you rely on it, and treat your contract manager as the authority rather than this page.