IN THE last 10 years many new twin-bore tunnels constructed around the world have been provided with cross connecting doors at road level at intervals varying between 100-500m, which permit self-rescue escape for someone with reduced mobility using a wheelchair.
However, the new concept of double deck Duplex tunnels such as A86 around Paris, which was opened in 2009, have been built with interconnecting staircases between levels, along with periodic refuges, as part of their escape strategy. A new eight lane, double deck cut and cover tunnel through Maastricht in the Netherlands is likely to pose similar challenges for those with disabilities or reduced mobility.
With some 8,300 road tunnels of varying length, and a high proportion over 500m long, Japan can justifiably claim to be one of the leading Nations in terms safety provision with a specific criteria governing planning, design and operation, called the ‘National Safety Standard of emergency facilities on Road Tunnels’. While many of the older stock operated by Nexco Expressway Company feature elevated walkways of varying heights, the more modern twin tube tunnels have been constructed with spacious cross connection doors at road level at a maximum of 350m intervals.
Elevated concrete walkways, with handrails, are also extremely prevalent in tunnels across the USA. The ‘Americans with Disabilities Act’ (ADA) titles relating to ‘Public Transportation’ and ‘Public Accommodations’ along with the 1968 ‘Architectural Barriers Act’ (ABA) have not yet been amended to consider the safety provision for persons with reduced mobility, with no reference within the applicable NFPA Design Standards 502 or 101 (chapter 7) to meet the needs of either elderly or disabled during evacuation.
In the United States there appears to be an assumption everyone has the ability to climb steps in an emergency and that when necessary the physically strong will assist those less able. That said, recently opened tunnels such as the fourth bore of the Caldecott in California, and Port of Miami, have gone some way to being accessible from road level, despite the inclusion of elevated walkways, but the design of Highway 99 Seattle ‘big dig’ tunnel has followed the Paris model with a Duplex double road deck connected by stairs to a central evacuation gallery. When completed, disabled persons will have to wait in a shelter until rescued by fire fighters. The situation in Australia is not dissimilar, with no specific reference in individual State Tunnel Design codes. A number of the current tunnels have elevated walkways which necessitate climbing stairs to access emergency exits, however exits in the new Legacy Way Tunnel in Brisbane are step free but culminate in a sliding door which may require the assistance of an able bodied person to open.
The position around Europe is mixed, with a good proportion of accessible exits to be found in Austria, Switzerland, Spain, Netherlands, and France to name but a few with the later setting the ‘safety’ bar extremely high, in terms of technological features and operational processes, within the refurbished 11.6km long Mont Blanc tunnel. Nevertheless, connection between the pressurised shelters and the invert final escape route is still via staircases. Norway meanwhile, has 1,100 road tunnels including the Laerdal, the World’s longest at 24km, and specifies differing levels of safety equipment provision depending upon the tunnel length and traffic volume.
As far as can be ascertained only Germany has acted to amend its ‘Federal Highways Act’ (FStrG) and ‘Guidelines for Furnishing and Operating Tunnels’ (RABT) in light of the UN Charter, the EU Directive, and the German Federal Act on Equal Opportunities for the disabled.
While the United Kingdom is in the process of updating its Tunnel design code BD78/99 to reflect the contents, and impact, of the Regulatory Reform (Fire Safety) Order 2005, the Road Tunnel Safety Regulations 2007, and the Equality Act 2010, new tunnels such as Hindhead and Tyne Tunnel 2 were designed with universal accessibility in mind while the original Tyne Tunnel was transformed internally with the creation of an accessible fire proof escape corridor over its full length. Operators of existing Highway England and Welsh Government tunnels have also made ‘reasonable adjustments’ wherever possible. There are several older tunnels however, such as Blackwall and Rotherhithe in London, where the physical and operational constraints have so far restricted any noteworthy adaptation.
Above And beyond
But one UK Tunnel Owner/operator, Merseytravel, has gone well beyond ‘reasonable adjustments’ and in the process of upgrading ‘Kingsway’ and ‘Queensway’ Mersey tunnels between 2002 and 2006, set a benchmark in the escape provision for persons with reduced mobility. There are two tolled road tunnels beneath the River Mersey. The older of the two is called ‘Queensway’ and was opened in 1934 while a second twin bore tunnel, known as ‘Kingsway’ was opened in 1971 and between them they have a combined annual throughput of around 26 million vehicles.
In the wake of the 1999 Mont Blanc and Tauern tunnel fires, Merseytravel reacted by first reviewing its existing evacuation provision in the Kingsway Wallasey Tunnel (via elevated walkways) and then in 2002 authorising the construction of three additional 17m long cross passages – spaced at around 300m apart – between the two tubes. A key component of the design and delivery was that the new permanently illuminated escape passages should be at road level, and step-free, to make them fully accessible to persons of reduced mobility.
Three years later Merseytravel embarked upon a further multi million pound investment to upgrade the escape provision in the Queensway Birkenhead Mersey Tunnel with particular reference to the requirements of disabled and others with reduced mobility.
Following a study of all the options plus a series of trials by the design team, the concept adopted was to cut through the side-walk, and road deck, at approximately 200m intervals, prop the deck structurally, and then construct ramps, rather than stairs, within a stainless steel fire protected entrance, with integral crash barrier. Thus, refuges and ramps were contained within the 44ft (13.4m) diameter envelope, avoiding further excavation through the tunnel lining.
These ramps would lead escapees, via a series of twohour rated fire protected doors, to seven refuge chambers (all linked to a connecting escape route) situated in the airway invert beneath the road deck, and there they would stay until the incident was deemed over by emergency services. A further stage of the design process focused upon the spatial requirements within escape passages for ambulant and non ambulant evacuees, those in wheelchairs, and even fire-fighters carrying a stretcher, with particular emphasis on the required envelope and the gradients of the ramps.
The design of the ramps was based upon downward gradients of 1:12 and 1:20, with landings, complying with UK Building Regulations part M, however to prove the design, and reduce the length of travel to ‘reasonable’ proportions, ramps were designed to oppose the tunnel gradient and a full scale prototype of a shelter entrance with a variable gradient ramp was constructed off site, tested and approved by disabled groups and RADAR members. In the end it was found that a 1:8 ramp was acceptable in this instance.
When Queensway Tunnel safety upgrade was completed in 2006 the following facilities had been introduced with the specific intention of meeting the needs of persons with reduced mobility in the event of an emergency evacuation.
¦Step-free access via non slip ramps to seven pressurised safety refuge chambers beneath the road deck.
¦All two-hour fire rated doors fitted with vision panels and push bar opening.
¦Emergency SOS telephones in niches adjacent to refuge
entrances positioned at a height accessible to someone in a wheelchair. CCTV coverage for entrances, ramps and refuges all linked to the Tunnel control room.
¦Extra-large green photo luminescent ‘man running’ signage to British and European standards indicating the entrance to a fire door.
¦An ‘active’ high-visibility evacuation system – triggered by Tunnel controllers – featuring an initial radio breakin message followed by a zonal PA instruction, green illuminated chaser arrows pointing towards the exit door, low level way finding signs indicating the distance to the nearest exit, high intensity strobe lighting around the door lobby plus a white noise directional sound beacon with ‘Exit Here’ voice-box for the benefit of those with impaired eyesight or persons in difficulty due to reduced visibility in the tunnel.
¦Each 180-person capacity refuge chamber provided with an accessible disabled chemical toilet, some seating, and a supply of fresh drinking water together with first aid equipment, orientation and instructional signs, and two-way audiovisual communication with a dedicated and specially trained handler in the tunnel control room.
¦Alongside each fire exit from the tunnel road deck, a lightweight, folding wheelchair was positioned within a touch button, easy access, enclosure for emergency use by those unable to access their own wheelchair or to facilitate transportation by a helper of a person whose mobility is compromised.
¦Enhanced lighting levels both in the main tunnel itself and on escape routes once an emergency evacuation is in process.
¦At the two points, some 1,500m apart, where the invert escape route walkway terminates at a staircase shaft to the surface, a standard ambulance sitting stretcher with wheels has been provided in an easy access enclosure for the use by emergency services only to transport a non-ambulant person up stairs to the surface.
¦Standard operating procedures were re-drafted to ensure rescue priority is given to assisting, any persons in difficulty due to reduced mobility including the elderly and young families.
POSSIBLE TECHNOLOGICAL ENHANCEMENTS
Given that there is no universal means to externally identify a vehicle carrying a disabled person (such as a plate on the rear) the authors would wish to explore the possibility of adapting the current flashing ‘hazard light’ system incorporated in all cars, so that in a vehicle used by, or registered to, a disabled person they are adapted to flash at a recognisably different intensity and frequency signalling the classic ‘S.O.S’ message. This would indicate to others the occupant is in distress, or importantly in a tunnel situation, trapped in their vehicle. The authors recognise the difficulty in achieving consents for this, but would argue this simple adaption to hazard flashers on vehicles carrying disabled persons would be universally recognised by rescue crews and many other drivers, both on the open road and in tunnels.
The means of detecting the presence in the tunnel of a person or persons with an impairment to mobility stranded in their vehicle have been explored, and the following is proposed.
¦ By utilising Automatic Number Plate Recognition (ANPR) upon entry and exit, tunnel operators will be able to identify specific vehicles registered to disabled drivers and potentially track their passage through the tunnel on CCTV.
¦ In the UK, all vehicles adapted for, or registered to a higher level of disabled person are exempt from road tax, and are therefore identified as ‘special needs’ within the registration hierarchy. Thus, in the event of an incident, a tunnel operator, with appropriate levels of permission, would be able to connect to the DVLA (or equivalent vehicle registration organisation outside the UK) database for vehicles registered to disabled persons and cross check it in seconds against known vehicles stopped inside the tunnel. It is suggested this system is called ‘Mobility Impaired Recognition System’ (MIRS).
¦ This would enable the tunnel controller to identify any vehicles where the occupants may have mobility difficulties in evacuating their vehicles, and then alert emergency services or tunnel rescue teams.
¦ A very notable exception from the DVLA database though are persons with hearing impairment, who might well be at a disadvantage compared to persons with physical disabilities. Currently in the UK vehicles used by persons with reduced or total loss of hearing do not qualify for tax exemption – as they are not adapted – so Operators would not be aware of the presence of persons suffering this type of disablement.
¦ This is particularly relevant given most evacuations are initiated by radio break-in messages, instructions via public address systems, and directional sound beacons over exit doors, thus highlighting the need for visual and active signage.
¦ The ‘MIRS’ facility referred to above could be utilised both in the event of an incident where a single vehicle has broken down in the tunnel or multiple vehicles have stopped due to a Road Traffic collision, a vehicle on fire or similar emergency. The detection of stopped traffic and a related incident is carried out by means of video, radar, thermal imaging or audio listening systems, collectively referred to as AID (Automatic Incident Detection), however, the authors consider MIRS would operate independently to AID systems.
The likelihood of a person left behind in their vehicle once evacuation has commenced is particularly applicable for those whose mobility is reduced by a disability, but certainly not exclusive. Paralysis induced by fear can incapacitate some drivers and passengers so detection of those vehicles where there is no immediate pedestrian movement during evacuation is paramount for the occupant’s safety. A methodology and means to enhance AID systems responses is explored as follows.
¦ During an incident when multiple vehicles are stopped within a tunnel it is normal practice for the AID system to inhibit further alarms so the tunnel controller is not expected to acknowledge multiple warnings of a stopped vehicle, as he will be aware after the first incident alarm. If an instruction to evacuate is given by all available technological means, there is likely to be a period of extensive pedestrian movement, which again will normally trigger alarms.
¦ While the proposed MIRS system is one means of highlighting to controllers the presence of a vehicle carrying a disabled person, a second option is available as it is also technically feasible to create a new base line for the AID system, specifically for the background data, initiated by a simple button click, once a queue of standing traffic has formed. The queue of vehicles would then become part of the background data and anything extra to this, such as pedestrians, will become easier to identify.
¦¦Conversely, where there is no pedestrian movement from a standing vehicle, i.e. the doors have not opened and the occupants have not extricated themselves inside an agreed timeframe, this would be highlighted by the AID system as an ‘alarm’ behaviour, at which point the controller could address the occupants via the PA system, and in the event of no apparent response, direct rescue crews towards the vehicle.
¦¦The authors have consulted a major worldwide manufacturer and installer of automatic incident detection systems and received a positive response with a new background level to cover queuing traffic and alarm status for non-movement around a vehicle considered technically feasible with some extra cost to develop. Such an enhancement would add significant value to the use of such systems.
POSSIBLE ENHANCEMENTS
If fixed or variable message signs exist on the adjacent highway network approach to a tunnel, they should display a picture indicating drivers should leave a minimum distance of 3m when stopped behind another vehicle during a traffic stoppage or congestion. This will allow sufficient clearance to operate a wheelchair lift. In addition, operators could better utilise available tunnel safety systems such as in-tunnel variable message signs and radio re-broadcast to interrupt with brief safety messages – targeted at anyone with reduced mobility.
In the UK all new ‘Motability’ adapted vehicles for disabled are automatically fitted with tracking devices – ostensibly to prevent fraudulent use, but regular users of a route which includes passage through a tunnel could, theoretically, be targeted with evacuation/emergency instructions and operators alerted of their registration number. Additionally, all ‘Motability’ scheme vehicles are registered with the DVLA as some used by persons with higher levels of disablement are exempt from payment. With increasing use of ANPR for congestion charging, road, tunnel and bridge tolls, a vehicle registered with the DVLA (or similar registration plate issuing organisation) as being owned, or used exclusively, by a disabled person, can be almost instantaneously identified via its number plate, enabling a Network or Tunnel operator to receive a warning alert before, or just after, it enters a tunnel. In the event of an incident and evacuation, the alert will be logged and operators can notify on-road staff to target the vehicle for special help.
A folding aluminium standard wheelchair can cost as little as GBP 160 (USD 240), yet is a potential lifesaver to anyone trying to assist someone who are either unable to access their own wheelchair or is compromised by their inability to walk the distance to a place of safety unaided. Emergency wheelchairs should, therefore, be provided in suitable easy access enclosures at periodic positions along the length of a tunnel possibly as part of each emergency point/ SOS telephone niche.
Improved education for drivers on how to behave in a tunnel emergency is another important factor to consider. If there is a toll plaza, operators should give out an instruction leaflet with tickets, promote the tunnel evacuation strategy on corporate and News web-sites, and seek to use all media outlets to publicise how both able bodied, and disabled, should respond to an evacuation instruction. Such messages must underline that staying in a car is not an option. Understanding the significance of adapted hazard warning lights as proposed in this article would also form part of the UK Highway Code, theoretic driving test and international equivalents.
If the staircase to a refuge, or escape gallery, is of relatively short assent and of sufficient width to permit escape by three persons side by side, consider the installation of a wheelchair lift, or inclined platform lift, to one side. If it is not possible to dispense with stairs altogether in favour of accessible ramps, the shaft design of tunnel escape staircases should at least cater for the installation of an evacuation/fire-fighting platform lift capable of carrying a wheelchair up to 400kg over seven metres of travel.
Many tunnels already have public address systems enabling controllers to convey a series of standard pre-recorded messages to stopped traffic in an emergency, the content dependent upon the situation in that particular zone. A further series of focused, more reassuring messages, should be developed to address any vehicle(s) where CCTV or AID has identified the occupants have declined to, or are struggling to, evacuate their vehicle within set timescales.
Even allowing for the interpretation of what constitutes reasonable adjustments to existing infrastructure, it is clear from our research there needs to be a sea change in attitude by tunnel designers, operators, highway owners, and in some cases, governments, to ensure the rights of disabled persons, and the wider group of those whose mobility may be compromised during an emergency, are protected to deliver the ‘Universal accessibility’ all nations committed to in the 2006 UN Charter.
It is the authors’ hope this article, and their presentation of a paper on the same subject at the World Road Congress in November 2015, will challenge thinking in some parts of the world and hasten change which will one day save the lives of those less able during a tunnel emergency.
