Issues associated with requiring bridge plate car ramps to be 

automatically deployed and connected to the cars

Preliminary DRAFT for discussion purposes only.

This is not an official position paper.

Currently most wheel chair ramps used in commuter applications are portable and in the 

case of LIRR and MNR they are manually deployed when necessary by the train crew. 

LIRR and MNR store ramps on the equipment near the wheelchair seating areas, as well 

as on certain station platforms to ensure that the ramps are readily available when needed. 

This manual effort allows the train crew to ensure the safety of boarding and alighting of 

passengers with wheelchairs and mobility devices to and from the train, while not 

interfering with rapid passenger flow on most cars at most stations.

If automated ramps are applied to the car they will reduce the safety of boarding and 

alighting for passengers with wheelchairs and more so for walking passengers on all cars 

at all stations. In addition, the complicated deployment system and associated safety 

interlocks required for their use will increase station dwell times, significantly increase 

procurement and maintenance costs, and car weight and reduce the overall reliability of 

the transportation system, while providing minimal benefits for passengers with mobility

aide devices such as wheelchairs.

There are safety concerns associated with the use of automatically deploying bridge 

plates which are exacerbated by the requirement that all accessible doors of all cars

use the device at every single station stop, even when there may not be a need for the 

devices at any stations on a particular train and even when only one station may 

need to have a bridge plate. Currently, the manually deployed bridge plates are used 

only on the car that they are needed and only at the stations that they are needed. The 

safest boarding and alighting for everyone is to have level boarding with minimum gaps, 

which for most authorities, can be achieved only at certain stations. Some of the safety 

concerns related to the use of automated car ramps are as follows:

1. The deployment of the bridge plate will pose a safety hazard to passengers on 

the car as well as passengers on the platform. In order for the ramp to fold out 

onto the platform it will likely be stored inside the car and likely inside the 

vestibule in a locker and deploy to the outside of the train onto the platform when 

the doors open. 

A. Passengers in area for deployment on the car will need to be kept clear 

so that no one is injured during the deployment. Currently many rush 

hour trains are filled to capacity and people are standing in the vestibule. 

Keeping the vestibule clear of people is nearly impossible as passengers

need to traverse the area during boarding and alighting. Additional audible 

and visual alarms will be necessary to warn passengers to move from the 
vestibule areas. However when the cars are filled to capacity, which is 

likely during peak periods , it will be impossible for them to clear out of 

vestibule areas, and thus it will not be possible to safely open the doors 

and deploy the bridge plates. Therefore under these conditions opening the 

door will create a safety concern at every accessible door with crowded 

vestibules on the train. Even when the train is not overly crowed, 

passengers generally congregate at the vestibules before their stop, so that 

they are ready to alight when the train comes to a stop. 

If a fold out bridge plate is used, the doors will need to open before the 

bridge plate can fold out onto the platform. If will be difficult to prevent 

walking passengers from walking through the door if it is open, 

consequently it will be difficult to tie the bridge plate actuation to the door 

operation.

B. Passengers on the platform waiting for a train must clear the area 

when a train arrives so that they do not get hit by the deploying 

bridge plates. Keeping the platform area clear of passengers will be very

difficult. Typically passengers stand near the door openings when the train 

arrives so that they can get on and get a seat. Often the passengers are so 

close to the door that they obstruct passengers getting off the train. In 

addition, identifying the areas of bridge plate deployment on the platforms

will be difficult because the car doors do not always align with the same 

exact location on the platform. This misalignment can be due to 

differences in door spacing on different equipment and/or accuracy of 

train berthing at platforms. The deploying bridge plates will take up 

significant space on the platform depending on the length of the bridge

plate which can be 12 inches to 18 inches for vertical gap between 3

inches and 6 inches and significantly longer for larger vertical gaps, and 

larger horizontal gaps. The bridge plate for all accessible doors on all

cars will need to be designed to accommodate the largest vertical gap 

present on the system as well as the largest horizontal gap on the 

system, which could be quite large due to platforms on curves.

Additionally for locations where the car threshold is lower than the 

platform an additional limited rotation hinge would need to be added to 

the bridge plate to allow it to conform to the height difference. A straight 

rigid plate would not work in these instances.

C. Since only newer cars would be equipped with the new devices not all 

trains will need to clear the vestibules and platform areas at station 

stop as outlined above. This would require that the customers know the 

difference between new cars and older cars so they are prepared for the 

device to deploy. There will be a learning curve for regular commuters, 

but it will always be difficult to teach transient customers. 

A manually deployed bridge plate operation allows the train crew to clear the area 

on the platform and in the car vestibule before deployment of the bridge plate.

Since the bridge plate operation is not tied to the doors, train crew personnel can 

open the doors and then wait for crowds to disperse before deploying the bridge 
plate. This deployment process mitigates the hazards to passengers with and 

without mobility devices associated with automatic deployment outlined above.

2. Once folded out the bridge plate will be a tripping hazard to persons on the 

station platform walking on to or off the train. The bridge plate will extend into 

the platform area 12 inches to 16 inches or more. This will require that every

walking passenger at every single door opening at every single station will need 

to use the entire ramp. On crowded platforms it may be difficult to see the ramp. 

For persons with visual impairments it may also be difficult to sense the ramp.

People exiting the train may attempt to walk off the sides of the ramp instead of 

proceeding down the entire length, which will create a tripping hazard. Similarly

people entering the train may attempt to step onto the side of the ramp near the 

door, instead of walking the entire ramp, which will create a tripping hazard.

3. Once folded out the bridge plate will be a tripping hazard to persons on the 

train attempting to board or alight. The platform will need to fold out and sit on 

top of the finished floor, which will create a tripping hazard as people generally

expect a flat floor without steps once they walk onto a train and are typically not 

looking down as they walk. 

4. In order to ensure that the plates are only deployed when stopped at a station 

and the doors are open, safety interlocks will need to be provided between 

the bridge plates and the side door and/or car propulsion system. The 

interlocks will prevent the car from moving when the plates are extended and 

prevent the plates from extending when the car is moving or the doors are 

purposely kept closed. Should any of the interlocks fail an unsafe condition would 

exist, therefore the sensors would need to be redundant to reduce the likelihood of 

a false indication. Consequently the high number of sensors increases the 

likelihood that a train will be prevented from moving due to a failed sensor or 

failed actuating device. To address these concerns by pass devices would need to 

be provided to allow train movement in case of an emergency due to sensor and 

or device failure.

5. Inclement weather conditions will create additional safety concerns. Built up 

snow and ice on the platform, vestibule and bridge plate will inhibit deployment 

and retraction of bridge plate. This may result in the bridge plate being prevented 

from fully deploying or retracting or properly interfacing with the platform which 

will cause unsafe conditions for the passengers attempting to board and or exit the 

train. This will also result in train delays since operation will be tied to train 

movement.

In addition to the safety concerns outlined above there are additional concerns with the 

automatically deploying bridge plates which include complexity of the device, storage 

space, increased station dwell times, infrastructure restrictions, significantly increased

procurement and maintenance costs, car weight and reduced overall reliability of the 

transportation system. These concerns are explained in more detail below:

1. In order to meet the slope, stowage and range of vertical and horizontal gaps 

required by the regulation and automatically deploy and retract safely the 
design of the device may be more complicated than it may appear. If stored 

on the vestibule wall, the device would need at least two hydraulic or electrical 

motion devices or a single motion device and a mechanical actuating device, so 

that it can fold onto the vestibule floor then fold onto the platform. If space is a 

constraint, additional levels of folding may be required to fit in the available 

space. In order to allow for deployment or retraction due to device failure, 

mechanical back systems would need to be provided to deploy and retract the 

device, further complicating the system design. Due to concerns of snow and ice 

build-up under freezing conditions, heating provisions or other methods will be 

necessary to clear the bridge plate, and platform and bridge plate of built up snow 

and ice. 

2. In order to meet the slope, stowage and range of vertical and horizontal gaps 

required by the regulation and automatically deploy and retract, the size of 

the device will be quite large. The size will vary depending upon the 

infrastructure present at each operating authority. Since the bridge plate for all 

accessible doors on all cars will need to be designed to accommodate the largest 

vertical gap present on the system as well as the largest horizontal gap on the 

system, it may be much larger than necessary at most stations. The length of the 

bridge plate will need to be at least 20 inches long to provide some overlap on the 

car floor and meet the slope requirements for typical 3 inch to 6 inch vertical gap. 

Secondly the device will need to span the entire door width so as not to create a 

tripping hazard and provide the necessary passenger flow rates required. Many

authorities including LIRR and MNR typically have 50 inch wide door openings. 

In order to accommodate both positive and negative vertical gaps, the ramp will 

either need to have a curved arch or have a flexible hinge, both of which will take 

up additional space for storage of the ramp alone. Add to that operating 

mechanism and the size of the storage space for the ramp will be on the order of 

50 inches by 20 inches by about 8 inches of depth. For a typical commuter rail car 

with 4 doors this would be equivalent to a box of 50 inches by 20 inches by 32

inches, which is significant for a commuter car where every inch of space counts. 

When considering that some subway cars have more then 4 openings per car, the 

amount of space occupied by the devices is even greater. 

3. Deployment and retraction of the devices will increase dwell time at each and 

every station stop. It is estimated to take approximately 20 seconds or more to 

safely deploy the bridge plate and another 20 seconds or more to retract the bridge 

plate. In addition there will need to be an additional waiting period of at least 20 

seconds to allow for the vestibules to clear, before the bridge plate can be 

deployed. Considering there is only 3-5 minutes to load and unload a train 

during rush-hour conditions, the additional time required on top of the current 

time required for opening and closing doors will require that additional time be 

spent at the station reducing the capacity of the transportation system to more 

people, which will lead to more crowded trains.

4. Deployment of the device may not be possible at all station locations due to 

existing infrastructure. The existing infrastructure at stations including columns 

and other obstructions would prevent the deployment of the devices. Considering 

the size of the devices is approximately 15 inches long and 50 inches wide, there 
simply is not always enough space at every door opening to accommodate the 

fold out bridge plates.

5. Due to the complexity of the system as outlined above the cost of purchase 

and maintenance of the devices would be significant. Maintenance costs would 

include the added expenses associated with maintaining a significant new pool of 

spare parts from a single source of supply and addressing obsolescence issues 

associated with complicated controls systems available only from the OEM. 

6. Additional weight associated with the implementation of bridge plates is not 

insignificant. Heavier cars use more energy to move. Federal carbody safety

regulations require significant structure which adds weight to rail cars. Many 

operating agencies are at the limits for weight for their vehicles. Consequently the 

authorities and the car builders are always looking for ways to reduce the weight 

of the rail cars. A rough order of magnitude estimate of the weigh associated with

one device is 200 pounds. Considering that there are typically 4 doors on each car, 

the increase in weight per car would be 800 pounds.

7. Due to the complexity of the system as outlined above and the required 

interlocks associated with safe operation, the overall reliability of the rail car 

will decrease. As outlined above, the bridge plate system will require several 

new components, which if failed would prevent the car from continuing in service 

carrying passengers. Every new component added to a rail car that can fail, and 

prevent the rail car from continuing in service reduces the reliability of the car and 

the transportation system.

Near level boarding is generally considered the best boarding and alighting condition for 

everyone, and most authorities expend money and resources to reduce the gap to the 

extent practical but cannot achieve compliant small gaps at all stations. Considering the 

difficulty associated with bridge plates, would it be better to have more stations with 

small gaps, especially high transfer stations, and use bridge plates only when necessary

than to require everyone use a bridge plate at every station, even those with very small 

gaps? By requiring bridge plates be used at all stations by requiring automatic 

deployment, you are providing an incentive to increase the gaps at the stations with small 

gaps since bridge plates will be required at these stations due to possibly a few problem 

stations on the infrastructure. The one size fits all approach, dictated by an interpretation 

of the proposed requirement is not in the best interest of all passengers.