Recommendation R15-02

Assessment of the response to Rail Safety Recommendation R15-02

View document in PDF

You need a PDF reader to access this file. Find out more on our help page.

Bus crashworthiness

Background

On 18 September 2013, at about 0832 Eastern Daylight Time, westward VIA Rail Canada Inc. (VIA) passenger train No. 51 departed from the VIA Ottawa Station on time and proceeded en route to Toronto. At 0847:27, OC Transpo double-decker bus No. 8017 departed from the Fallowfield Station on the OC Transpo bus Transitway. At 0848:06, while proceeding at about 43 mph, the train entered the OC Transpo Transitway crossing, located at Mile 3.30 of VIA's Smiths Falls Subdivision. At the time, the crossing lights, bells and gates were activated. The northbound bus was travelling at about 5 mph with the brakes applied when it struck the train. As a result of the collision, the front of the bus was torn off. The train, comprising 1 locomotive and 4 passenger cars, derailed but remained upright. Among the bus occupants, there were 6 fatalities and 9 serious injuries, and about 25 minor injuries were reported. No VIA crew members or VIA passengers were injured.

The Board concluded its investigation and released report R13T0192 on 02 December 2015.

TSB Recommendation R15-02 (December 2015)

Structural deformation can be beneficial during a collision as energy is absorbed and dissipated that would otherwise be transmitted directly to the occupants. The basic principle of crash energy management is to ensure that, during a collision, the unoccupied spaces deform before the occupied spaces. Survivability is influenced by how well the impact is absorbed by features of the vehicle and directed away from the occupants. Any structural damage of the container should not reduce the size of the survivable volume or open it up to the elements to the point where it compromises occupant survivability.

Transport Canada (TC), through its Motor Vehicle Safety Directorate, sets safety standards for the design, construction and importation of motor vehicles in Canada. These standards are known as the Canada Motor Vehicle Safety Standards (CMVSS) and are governed by the Motor Vehicle Safety Act and the Motor Vehicle Transport Act through the Motor Vehicle Safety Regulations. The Motor Vehicle Safety Regulations specify the requirements respecting safety for motor vehicles and related components. Pursuant to the regulations, the CMVSS identify the prescribed tests required for the certification of vehicles of various weight categories.

The CMVSS requirements vary according to the weight and type of vehicle. The heaviest vehicle weight category includes tractor-trailers that transport commodities and most transit and interprovincial buses that can transport up to 100 passengers. While these vehicles must meet a baseline of essential safety criteria (brakes, steering, etc.) and there are some vehicle safety standards that apply only to this weight category, these vehicles are generally subject to the fewest safety standards. The ADL E500 buses were designed in accordance with, and were fully compliant with, the legislative requirements of the Federal Motor Vehicle Safety Standards (FMVSS) in the United States and the CMVSS, as well as all applicable state and provincial requirements.

In this occurrence, 4 of the 6 fatally injured occupants were seated in the front row on the upper deck of the ADL E500 bus, which was an area that was structurally compromised during the accident. During the accident, the framing of the upper deck and lower deck floor was torn away. The failure of the bus structure ultimately resulted in the driver, the driver station and seat as well as 8 passengers and 4 passenger seats on the upper deck being ejected from the bus. Although the ADL E500 met all regulatory requirements, the front-end framings were not designed to provide any impact protection for upper deck occupants seated in the front row, and there was no front bumper, nor were these features required by the CMVSS.

During the investigation, other bus designs were reviewed for comparison. The following observations were made:

  • Passengers positioned behind the yellow line – Passengers standing on a single-deck bus and passengers standing on the lower deck of a double-decker bus are required to be behind the yellow line located on the floor just behind the driver's station.
  • In this accident, although a number of passengers on the lower deck were injured, only 1 passenger standing behind the yellow line sustained fatal injuries. In comparison, all 4 passengers seated in the front row of the upper deck, a location that was directly above the driver station and forward of the yellow line, sustained fatal injuries. Therefore, under the same circumstances, it is less likely that passengers on a single-deck bus would have been exposed to an area that was compromised by the collision.
  • School bus – School bus design includes elements that are meant to reduce the effects of a collision. School buses must meet rollover protection standards. They also have a raised underframe, increased body strength, full-length horizontal impact rails and interior compartmentalization. TSB Railway Investigation Report R13W0083 indicated that school buses have an increased ability to withstand an impact and to protect occupants during a vehicle accident.

Vehicles imported to Canada must conform to the applicable CMVSS for the type of vehicle. The manufacturer is responsible for conducting all tests required to meet the CMVSS and for providing copies of the test results to TC. TC reviews the test results and provides approval for importation. Otherwise, there is no formal inspection or risk assessment of the vehicle required prior to delivery, regardless of the vehicle design features.

In contrast, the American Public Transportation Association (APTA) has developed guidelines for the procurement of transit buses to help transit agencies prepare contracts that contain all necessary provisions and incorporate best available practices. The principal crashworthiness requirements in the APTA guidelines pertaining to transit buses include the following considerations (among others):

  • Technical specification (TS) TS 23.2 requires that a bus be designed such that, in the event of a rollover or side impact, its structure is sufficiently robust to maintain a survivable volume with only small permanent deformations allowed.
  • TS 70.1 requires the installation of bumpers to provide impact protection to the front and rear of the bus.
  • The technical specifications also include static and dynamic strength requirements for passenger seating and seat back handholds to minimize the potential for occupant injuries.

The APTA guidelines include crashworthiness requirements that exceed the requirements specified by the CMVSS and FMVSS. Federal regulations do not require compliance with the more stringent APTA guidelines.

Additionally, in a letter from the National Transportation Safety Board (NTSB) to the National Highway Traffic Safety Administration (NHTSA)Footnote 1, the NTSB outlined the findings from its special investigation,Footnote 2 which examined bus issues and evaluated the FMVSS that govern bus design. The NTSB was concerned that bus passengers may not be adequately protected in collisions. The investigation determined that, while standards within the FMVSS exist for large school buses relating to passenger seating, crash protection and body joint strength, there were no similar standards that applied to other types of large buses, such as motorcoach or transit buses.

The CMVSS contain no requirements for frontal impact, side impact, rollover or crush protection for vehicles with a gross vehicle weight rating (GVWR) in excess of 11 793 kg (26 000 pounds), which includes most transit buses. As a result, buses in this weight category can have different structural features that may not adequately protect the travelling public. Considering the consequences of this accident, the Board recommends that

The Department of Transport develop and implement crashworthiness standards for commercial passenger buses to reduce the risk of injury.
TSB Recommendation R15-02

Transport Canada's response to Recommendation R15-02 (February 2016)

Transport Canada (TC) acknowledges the recommendation.

TC also recognizes that extremely high forces were involved in the collision that are beyond reasonable expectations of structural integrity for any road vehicle.

TC will evaluate the existing crashworthiness of commercial passenger buses by undertaking a review of accident data from urban centres around the world, including this case, to identify leading risks. Should this analysis identify suitable opportunities for possible standards to improve crash safety on buses, it could then be used to guide the implementation of a crashworthiness test program at the Motor Vehicle Test Centre. If appropriate, guidelines for possible future standards could be prepared in consultation with stakeholders and published. If suitable opportunities for new standards are not identified during the process, a report on the analysis will be provided.

It is important to note that the United States does not currently have any structural crashworthiness standards in place for large commercial passenger buses. The United Nations vehicle safety regulations deal only with structural crashworthiness requirements during a bus roll over-type collision. Similar to the existing United States regulation, Canada expects to propose regulatory requirements for the installation of seat belts on many types of commercial buses. Any potential standard would only apply to new vehicles and as such would need to have a positive cost-benefit analysis to be considered for a mandatory requirement.

TSB assessment of Transport Canada’s response to Recommendation R15-02 (March 2016)

Transport Canada (TC) has acknowledged this recommendation.

TC will conduct a review of accident data from urban centres around the world to evaluate the existing crashworthiness of commercial passenger buses. TC indicates that, if the data analysis supports suitable opportunities for standards to improve crash safety on buses, the analysis could be used to guide the implementation of a crashworthiness test program, possibly leading to the development of guidelines for future standards in consultation with stakeholders.

The Board notes that TC will be examining accident data from around the world to identify leading risks for commercial passenger buses. Beyond this commitment, there are no explicit plans for the development and implementation of crashworthiness standards for commercial passenger buses to reduce the risk to passengers. Furthermore, no specific timeline has been provided for the planned review and analysis.

Therefore, the Board assesses the response to Recommendation R15-02 to be Satisfactory in Part.

Transport Canada's response to Recommendation R15-02 (February 2017)

TC is conducting a literature review that is expected to be completed by spring 2017. The analysis will help guide any crashworthiness test program.

The crashworthiness test program is contingent on acquiring a bus shell, either in part or in whole. TC has searched extensively to acquire such a shell, but has not yet been successful. TC is in discussions with industry to explore an approach, where industry could provide structural expertise, fabrication of test bucks, modifications and oversight of testing as required. It is possible that this could include both commuter bus test bucks, as well as transit bus test bucks.

The test buck structure(s) will be incrementally modified (strengthened) and subjected to acceleration pulses. The effect of incrementally strengthening the structure will be evaluated with respect to unrestrained occupant protection. Following completion of the test matrix and analysis of the data, a report on the findings and next steps will be prepared.  

The 3 year project is planned as follows:

  • Year 1: Acquisition;
  • Year 2: Construction/modification of sled buck preliminary testing; and
  • Year 3: Test completion, data analysis, report preparation. 

In addition, TC has issued a Canada Gazette, Part I publication to propose regulatory requirements for Electronic Stability Control on most truck tractors and buses with a Gross Vehicle Weight Rating (GVWR) greater than 11,793 kilograms (26,000 pounds). TC has received comments following the Part 1 publication and is now preparing the Part 2 submission.

TC is also preparing a Canada Gazette, Part I publication to propose regulatory requirements for the installation of seat belts on many types of commercial buses.

TSB reassessment of Transport Canada's response to Recommendation R15-02 (March 2017)

TC is conducting a literature review on bus crashworthiness that is expected to be completed by spring 2017. Following this literature review, TC will initiate a crashworthiness test program to be completed over 3 years. This project has been planned as follows: 

  • Year 1 – Acquisition of a bus shell (either in part or in whole).
  • Year 2 - Construction/modification of sled buck preliminary testing. 
  • Year 3 - Test completion, data analysis, and report preparation.

In the short term, TC has initiated a number of regulatory changes that are aimed at improving the safety of bus passengers. These potential regulatory changes include 

  • the requirement to have electronic stability control on most truck tractors and buses with a gross vehicle weight rating (GVWR) greater than 11 793 kg (26 000 pounds); and
  • the installation of seat belts on many types of commercial buses. 

The Board notes that TC will be completing its literature review on bus crashworthiness shortly, and has initiated a number of regulatory changes to improve the safety of bus passengers. The Board looks forward to the initiation and completion of the crashworthiness test program, which will include a report on the findings and next steps. 

The Board reassesses the response to Recommendation R15-02 as having Satisfactory Intent.

Next TSB action

The TSB will follow up with TC to obtain information on the timeline of the crashworthiness test program and will monitor the progress of the planned actions.

This deficiency file is Active.

Footnotes

Footnote 1

National Transportation Safety Board Safety Recommendation Letter to the United States National Highway Traffic Safety Administration, dated 02 November 1999.

Return to footnote 1 referrer

Footnote 2

National Transportation Safety Board, Bus Crashworthiness Issues, Highway Special Investigation Report NTSB/SIR-99/04, 1999.

Return to footnote 2 referrer