How many doors does a bus have to have?

At least two: paragraph 7.6.1.1 of Annex 3 to UN Regulation No. 107 sets the minimum at two, either two service doors or one service door and one emergency door. The minimum number of service doors runs from one to four depending on passenger count and class, and every double-deck vehicle must have two doors on the lower deck.

How many emergency exits must a bus have?

Paragraph 7.6.1.4 sets a minimum total number of exits per compartment or deck, from two for 1 to 8 passengers and crew up to eleven above 130, and the emergency exits are whatever is needed to reach that total once the service doors are counted.

How big does a bus emergency door have to be?

In Classes I, II and III the aperture must be at least 1,450 mm high and 600 mm wide, under paragraph 7.6.3.1.2. Classes A and B may instead use the Annex 7 figures of 1,250 mm by 550 mm, and the small Class B vehicles covered by Annex 3 paragraph 7.7.1.10 have an Annex 7 minimum of 1,100 mm by 550 mm.

Does a toilet cubicle count as a separate compartment for exit purposes?

No. Paragraph 7.6.1.4 states that toilet compartments and galleys are not separate compartments for the purpose of defining the number of emergency exits, so they do not trigger a second exit count.

Bus Doors and Emergency Exits Under UN Regulation 107

Q: What opens a bus door when the electrics fail?

Paragraph 7.6.5.1 requires every power-operated service door, in the event of an emergency, to be capable of being opened from inside — and from outside when not locked — by controls that work whether or not the power supply is operating, with the vehicle stationary or at 3 km/h or less.

A bus is counted twice for exits, by two separate tables. The first asks how many service doors the vehicle needs. The second asks how many exits of every kind it needs in total, service doors included. A Class III coach with 46 to 60 people in its saloon can satisfy the first with a single service door and still owe five more exits under the second — our reading of the two tables together.

Which rulebook, and which of them is still in force

The instrument is UN Regulation No. 107. Paragraph 1.1 applies it to every single-deck, double-deck, rigid or articulated vehicle of category M2 or M3, and paragraph 1.2 lifts four kinds out again: vehicles for the secure transport of persons, for example prisoners; vehicles specially designed for the carriage of injured or sick persons; off-road vehicles; and vehicles specially designed for the carriage of school children. Paragraph 1.3 then applies it to vehicles designed for use by police, security and armed forces, and to vehicles whose seating is intended solely for use when stationary but which are not designed to carry more than 8 persons besides the driver in motion (mobile libraries, churches and hospitality units are the examples given), “only to the extent that they are compatible with their intended use and function”. The Regulation takes its categories from the UN’s Consolidated Resolution on the Construction of Vehicles (R.E.3); in EU law Article 4(1)(a) of Regulation (EU) 2018/858 fixes them — M2 and M3 both carry more than eight seating positions in addition to the driver, divided at a maximum mass of 5 tonnes.

The European Union once wrote its own bus construction rules and no longer does. EUR-Lex records Directive 2001/85/EC as no longer in force, end of validity 31 October 2014, repealed by Regulation (EC) No 661/2009; that regulation is itself no longer in force, end of validity 5 July 2022, repealed by Article 18 of Regulation (EU) 2019/2144, which applies from 6 July 2022 under Article 19. Which version of R107 the Union points at is a separate question from which one you read. Annex II to 2019/2144 lists UN Regulation No. 107 as requirement F14, “General bus construction”, marked A for M2 and M3, but it names no series of amendments. Annex I, the list of UN Regulations referred to in Article 4(2), in the consolidation to 2 August 2026 still gives R107 at the 07 series of amendments, published in OJ L 52 of 23 February 2018, for M2 and M3. The notes to that table say the series listed “reflects the version that has been published in the Official Journal” and “is without prejudice to the series of amendments that shall be complied with on the basis of the transitional provisions provided therein”; that compliance with a later series “shall be accepted as an alternative”; and that the dates in the series of amendments “apply on a compulsory basis for the purposes of Articles 48 and 50 of Regulation (EU) 2018/858 except where alternative dates are specified in Annex II” — and the F14 entry of Annex II names none. Paragraph numbers throughout this article are those of the 11-series text, republished in the Official Journal on 29 January 2026 and incorporating all valid text up to the 10 series of amendments, in force 8 October 2022, and the 11 series, in force May 2026.

Two counts, on two different populations

Paragraph 2.5 defines a service door as one intended for use by passengers in normal circumstances with the driver seated, and 2.8 an emergency door as one used as an exit only exceptionally and in particular in an emergency. Paragraph 2.11 makes an escape hatch an opening in the roof or the floor; 2.12 gathers emergency door, emergency window and escape hatch into “emergency exit”; 2.13 defines “exit” to take in the service doors, intercommunication staircases and half-staircases as well.

Paragraph 7.6.1.1 opens with a floor that has nothing to do with capacity: a vehicle shall have at least two doors, either two service doors or one service door and one emergency door, and every double-deck vehicle shall have two doors on the lower deck. Above that floor the service doors scale by class, and the classes are set out in bus classes under R107.

Minimum number of service doors — UN Regulation No. 107, Annex 3, paragraph 7.6.1.1.
Number of passengers	Classes I & A	Class II	Classes III & B
9 – 45	1	1	1
46 – 70	2	1	1
71 – 100	3 (2 in the case of a double-deck vehicle)	2	1
> 100	4	3	1

The second table, in paragraph 7.6.1.4, works on a different population: passengers and crew, per compartment or per deck.

Minimum total number of exits — UN Regulation No. 107, Annex 3, paragraph 7.6.1.4.
People per compartment or deck	Exits	People per compartment or deck	Exits
1 – 8	2	61 – 75	7
9 – 16	3	76 – 90	8
17 – 30	4	91 – 110	9
31 – 45	5	111 – 130	10
46 – 60	6	> 130	11

Two worked readings, both ours rather than the Regulation’s. A Class III coach seating 53 passengers with a driver and a courier takes one service door from the first table and, at 55 people in the saloon, six exits from the second — five emergency exits beyond the door. A single-deck Class I city bus rated at 95 passengers takes three service doors and, with the driver, nine exits. Neither total appears in the text.

How many doors a maker offers is a separate matter, and one manufacturer prints it as a tick matrix: MAN’s Lion’s City data sheets tick two or three doors for the 12, 12 G, 12 E and 10 E, three or four for the 18 and 19 variants, and two only for the low-entry 12 E LE.

What counts, and what does not

Paragraph 7.6.1.4 carries the counting rules too, and they cut in both directions. Each deck of a double-deck vehicle and each separate compartment is determined separately, but toilet compartments and galleys are not separate compartments for this purpose, so a coach washroom does not open a second count. Escape hatches can only count as one of the emergency exits in the table. Paragraph 7.6.1.6 is the generous one: a double service door counts as two doors, a double or multiple window as two emergency windows. Paragraph 7.6.1.3 is the strict one — a service door with a power-operated control system is not deemed an emergency door unless it can be readily opened by hand once the emergency control of paragraph 7.6.5.1 has been actuated, if necessary.

Articulated vehicles are treated as several vehicles. Paragraph 7.6.1.2 requires at least one service door in each rigid section, and two in the front section of a Class I articulated vehicle; paragraph 7.6.1.5 then treats each rigid section as a separate vehicle for the number and position of exits, except for the side-balance rule of paragraph 7.6.2.4, counts passengers per section, and states that the connecting passage between sections is not an exit. On a double-decker each intercommunication staircase is an exit from the upper deck under paragraph 7.6.1.13, and paragraph 7.6.1.14 requires everyone on the lower deck to reach the outside without entering the upper deck.

Escape hatches are not universal either. Paragraph 7.6.1.11 requires them on Classes II, III and B in addition to the emergency doors and windows — a minimum of one where the passengers (on the upper deck, in the case of a double-decker) do not exceed 30, and two where they exceed 30 — fitted in the upper deck roof only on a double-decker. For Classes I and A the same paragraph says only that, except as provided in paragraph 7.6.1.12, hatches “may also be fitted”, and it closes: “There shall not be any escape hatches fitted in the roof of a trolleybus.”

Where they have to be

For Classes I, II and III, paragraph 7.6.2.1.1 puts the service doors on the traffic side declared by the manufacturer on the communication form, with at least one of them in the forward half of the vehicle; the paragraph does not preclude a specially designed wheelchair door in the rear or side face, an additional rear door principally for goods or luggage, or additional service doors on the opposite side of vehicles designed for boarding on both sides. Classes A and B answer paragraph 7.6.2.2: the same rule on the side of the service doors, at least one exit on each side, and at least one in each of the forward and rearward halves of the passenger compartment.

Separation is prescribed rather than left to styling, and the figure turns on how many decks the vehicle has. The gate is in paragraph 7.6.2.3: where the passenger compartment has an area S0 equal to or greater than 10 m², two of the doors of paragraph 7.6.1.1 must be separated, the distance measured between transverse vertical planes through their centres of area. On a single-deck vehicle paragraph 7.6.2.3.1 sets that distance at “not less than” 40 per cent of the overall length of the passenger compartment, measured parallel to the longitudinal axis; on an articulated vehicle the same paragraph is met if two doors of different sections are not less than 40 per cent of the overall length of the combined passenger compartment apart, all sections counted. A double-decker is governed by paragraph 7.6.2.3.2, which measures on a different basis: not less than either 25 per cent of the overall length of the vehicle or 40 per cent of the overall length of the passenger compartment on the lower deck — and the requirement does not apply at all if the two doors are on different sides.

Paragraph 7.6.2.4 wants the exits, on each deck in the case of a double-decker, split substantially evenly between the two sides, though the same paragraph lets exits in excess of the required minimum number fall outside that split. Paragraph 7.6.2.5 requires at least one exit in the front or rear face, which paragraph 7.6.2.5.2 confines to the upper deck on a double-deck vehicle. Paragraph 7.6.2.5.1 gives Class I and A vehicles two further ways to satisfy it: fitting an escape hatch, or, where paragraph 7.6.1.12 applies — hatches “shall not be fitted in positions where technical components are installed which present possible danger to passengers using the escape hatches”, high-voltage systems among the examples given — fitting an additional exit on each side of the vehicle.

How big the aperture has to be

Minimum exit dimensions. Classes I, II and III from Annex 3, paragraph 7.6.3.1; Classes A and B may use these or the Annex 7, paragraph 1.1 alternatives. Annex 7 lets any service-door width be reduced by 100 mm when measured at the level of the handholds, and by 250 mm where intruding wheel arches, the actuating mechanism for automatic or remote-control doors or the rake of the windscreen require; an emergency door may narrow to 300 mm where intruding wheel arches require, “providing that the width of 550 mm is respected at the minimum height of 400 mm above the lowest part of the door aperture”; and paragraph 1.1.1 sets lower door figures (1,100 mm high) for the small Class B vehicles of Annex 3 paragraph 7.7.1.10.
Exit	Classes I, II, III	Annex 7 alternative for Classes A and B
Service door	Aperture must pass the access gauge of paragraph 7.7.1	Entry height 1,650 mm (Class A) or 1,500 mm (Class B); aperture height must pass the dual panel of Annex 3 paragraph 7.7.1.1; width 650 mm single (750 mm for Class B where the aperture height lies between 1,400 and 1,500 mm), 1,200 mm double
Emergency door	1,450 mm high × 600 mm wide	1,250 mm high × 550 mm wide
Emergency window	400,000 mm², taking a 500 × 700 mm rectangle; in the rear face, alternatively a 350 × 1,550 mm rectangle (paragraph 7.6.3.1.4)	400,000 mm², taking a 500 × 700 mm rectangle
Escape hatch	450,000 mm², taking a 600 × 700 mm rectangle	450,000 mm², taking a 600 × 700 mm rectangle

The aperture is only half the test. Paragraph 7.7.2.1 requires the route from the gangway to an emergency door to pass a dual cylinder — 300 mm diameter and 700 mm tall from the floor, carrying a second cylinder of 550 mm diameter, 1,400 mm in total — or, as the alternative paragraph 7.7.2.4 allows, the gangway gauging device. Paragraph 7.7.3.3 gauges an emergency window with a thin plate of 600 × 400 mm, corners radiused by 200 mm, or 1,400 × 350 mm with 175 mm corners at the rear face, and under paragraph 7.7.3.2 the plate, moved from the gangway to the exterior, “shall not meet any obstacle” — a window of the right area is not enough on its own. Where the first step rather than the aperture is the constraint, the step heights are in bus accessibility under Annex 8.

What opens the door when the power fails

Paragraph 7.6.5.1 answers the question through the controls. In the event of an emergency, every power-operated service door shall be capable, with the vehicle stationary or at 3 km/h or less, of being opened from inside — and from outside when not locked — by controls that work whether or not the power supply is operating, overriding all other door controls. Interior ones sit on the door or within 300 mm of it, at least 1,000 mm above the first step (the door referred to in Annex 8, paragraph 3.9.1 excepted), and are deactivated above 3 km/h.

Paragraph 7.6.5.1.6 sets the outcome and offers a choice of two: within eight seconds of the control being operated, either the door opens to a width the access gauge can pass, or it can easily be opened by hand to that width. The control may sit behind a cover that can be broken or removed, but paragraph 7.6.5.1.7 requires operating the control, or removing the cover, to be signalled to the driver both audibly and visually. Where the driver has locked out the exterior emergency controls under paragraph 7.6.5.2, they come back automatically either when the engine starts or before the vehicle reaches 20 km/h, and deactivation after that “shall not occur automatically, but shall require a further action by the driver”.

Emergency doors borrow the same controls. Paragraph 7.6.7.2 says emergency doors, “during their use as such”, shall not be power-operated unless, once a control complying with paragraph 7.6.5.1 has been actuated and returned to its normal position, the doors do not close again until the driver operates a closing control; the control must open the door to the width of the emergency-door gauge, or let it be easily opened by hand to that width, “within a maximum of 8 seconds”.

Where the window is toughened glass, the 2026 text times it. Under paragraph 7.6.8.2.2 a toughened-glass emergency window needs a device that lets one person break and remove each pane from inside within 20 seconds, which the technical service verifies by testing the device and measuring the time to a free opening. The device is marked in red, fixed adjacent to or on the window in the upper third of its height (the rear window, and positions where that is not technically compatible, have their own rules), and protected so that releasing it takes one additional action — and if it is electronic, paragraph 7.6.8.2.2.3 requires it to be operational in the event of a failure of the vehicle’s power supply. None of this device detail is in the 07-series text that Annex I to 2019/2144 lists: its paragraph 7.6.8.2.2 asks only that the window “be made of readily-breakable safety glass” and that “a device shall be provided adjacent to each emergency window, readily available to persons inside the vehicle, to ensure that each window can be broken”. Closing force is tested too. Paragraph 7.6.5.6 requires that a passenger be unlikely to be injured or trapped by a closing power-operated door, and 7.6.5.6.1.1 gives the first of two requirements deemed to satisfy it: a door resisted by a clamping force not exceeding 150 N at the measuring points of Annex 6 reopens automatically to its fullest extent, and the peak force “may be higher than 150 N for a short time provided that it does not exceed 300 N”. A front service door may instead meet paragraph 7.6.5.6.2 with soft edges.

What a used buyer can actually check

Marking is itself a requirement of the Regulation. Paragraph 7.6.11.5 requires every emergency exit, and any other exit meeting the prescriptions for one, to carry a pictogram from Table 3 of ISO 7010:2011 legible from inside and outside; 7.6.11.3 requires signs visible from inside to be photo-luminescent to at least sub-classification C in Table 2 of ISO 17398:2004.

Both tables are driven by numbers of people — passengers in the first, passengers and crew per compartment or deck in the second — so a change of capacity can move a vehicle into another row. Under paragraph 2.1.1.4 a vehicle “may be regarded as belonging in more than one Class” and “may be approved for each Class to which it corresponds”. The approval is granted to a series of amendments, and paragraphs 10.33 to 10.41 set how long earlier series are accepted. Under paragraph 10.33, as from 1 September 2026 contracting parties “shall not be obliged to accept” approvals to the series before the 10 series, though under 10.34 they “shall continue to accept” 06, 07, 08 and 09 series approvals for vehicles “not affected by the 10 series of amendments”. Paragraph 10.35 bars refusing 11-series approvals from its entry into force; from 1 September 2027 contracting parties “shall not be obliged to accept” approvals to any preceding series first issued after that date; until 1 September 2030 they “shall accept” 10-series approvals first issued before 1 September 2027; from 1 September 2030 they “shall not be obliged to accept” approvals to any preceding series, except that approvals to the 06 to 10 series stay accepted for vehicles “not affected by the changes introduced by the 11 series of amendments”. Paragraph 10.40 adds that contracting parties “may grant” approvals to any preceding series, and 10.41 that they “shall continue to grant extensions” of existing approvals to them. In the EU, the notes to Annex I of 2019/2144 construe “shall not be obliged to accept” and similar wording “as a binding provision for national authorities to consider the certificates of conformity to be no longer valid for the purposes of Article 48 of Regulation (EU) 2018/858”.

Three of these requirements can be compared with the vehicle itself. Count the exits against the passengers and crew in each compartment or deck, which is what paragraph 7.6.1.4 counts, rather than against the seats. At each power-operated service door, confirm that operating the emergency control, or removing its cover, is signalled to the driver audibly and visually, as paragraph 7.6.5.1.7 requires. Look for the pictogram on both faces of each emergency exit, and at each emergency window of breakable safety glass for the breaking device, which the 07-series text already required adjacent to each such window. Only a vehicle approved to the text containing paragraph 7.6.8.2.2.3 must also have the red-marked device, with “at least one of the following mitigating measures at the manufacturer’s choice”: permanently fixed “adjacent to or on each emergency window”, or a warning signal “audible or visible at the driver’s seating position” when it is temporarily removed. What the registration certificate records about seats and standing places is covered in buying a used coach, and what a maker’s sheet does and does not state in how to read a coach specification sheet.