The lighting fixtures in transit buses and railcars are virtually transparent to customers. Transit properties, however, view onboard lighting systems as key elements of their customer-service package because they impact passenger safety and comfort.

Interior lighting must meet a variety of specifications and still be both aesthetically pleasing for riders and structurally sound. And with new trends presented regularly to transit boards for consideration, companies strive to create innovative products that match ever-changing demands.

Technicalities
Lighting systems have been tailored by manufacturers to appeal to a variety of operations and are constantly being improved to better serve transit authorities and their riders. Optimal system performance can hinge on a variety of factors, such as choosing the correct ballast, lighting strip length and profile size.

The American Public Transportation Association (APTA) White Book lists a number of regulations and standards that must be met or surpassed by lighting configurations to be usable in a bus. Railcar standards require the same sort of compliance, though regulations are slightly different to meet application needs.

Similarities between bus and railcar lighting configurations are more prominent in looks than in technical specifications. While buses supply light with fluorescent systems, railcars have a variety of light source options, ranging from fluorescent tube systems to halogen lamps or LEDs. The type of source depends on the purpose of the car, but like buses, most railcars use fluorescent lights inside the cabin.

This general adherence to using fluorescent bulbs in transit vehicles has raised concerns for various agencies for a number of reasons. "We would like to get away from fluorescent tubes," says Dennis Elefante, manager of maintenance support services for the Orange County (Calif.) Transportation Authority. "They're a disposal problem for us. The ballasts can cause fires and we want to move away from that." Though this is not a common problem, safety issues with the high voltage of electronic ballasts make agencies wary of what could happen. Lighting companies have responded with research and development, and many have found ways to make ballasts safer.

Transmatic Group has taken into consideration its operations in other industries to improve its ballasts. "With our new ballast that we're introducing, it senses an arc in the lighting system and automatically shuts it off," says Tom Longanbach, marketing manager for the company.

New to transit interior lighting, this detection technology tracks recurring thermal events caused by changing currents, preventing problems in the lighting system.

Electric noise produced by lighting systems is another factor contributing to the dislike of ballast systems. Elefante says frequencies produced by fluorescent fixtures and ballasts can interfere with newer, more advanced devices installed on the bus.

Pretoria Engineering has developed ballasts that operate above an audible frequency to prevent device interference. They are part of an enclosed fireproof system to adhere to flammability requirements as well.

Because of the variety of railcar specifications, companies that provide lighting to rail systems tend to work hand-in-hand with the transit authority to design custom fixtures. Instead of offering general products, companies create designs specific to individual transit property requests.

System functionality
Lighting systems, in complying with safety standards, are much more complex in terms of parts and assembly than the average house lamp. Though governmental standards and APTA guidelines are manufacturers' top priorities, making sure systems are functional, easy to install and have as few components as possible are important as well.

When it's time to renovate or service a vehicle, agencies will choose products that are easy to take care of and do not require a lot of work to install — the longer it takes to work on, the longer the vehicle is out of service.

To make things less taxing on OEMs and agencies, lighting providers have designed systems with a number of snap-in parts and easy-access panels to make part repairs more efficient.

Specialty Manufacturing Co. purchased the U.K.-based transit interior lighting manufacturer Invertec in 2001 and adapted the company's product lines to meet U.S. specifications. The Covex line of systems is made of sections of lighting that are easily pieced together to create any length desired.

"We use alignment pins for the light extrusions so they'll mount up easier," says Pat Lock, transit sales manager for Specialty. "Our ballasts and the systems that we're using are easily accessible. We try to clean up the inside with wiring harnesses." Lock says the Covex design also has gasket material to keep dust and other airborne materials out of the system.

Vandalism, which is a chronic problem on public transportation vehicles, is also a concern with interior lighting. The L20 system, made by Transmatic, is a popular model in large transit buses and is made with vandal-resistant base panels to prevent serious damage. The materials in the panels are resistant to the damage of solvents used to remove graffiti and are layered to make puncturing difficult.

Good looks go a long way
The growing trend in the industry is installing applications that look good. "In the last few years, as the transit bus industry looks to expand into the suburbs and expand its reach, it has built buses that are more appealing for those areas," says Transmatic's Longanbach. "Agencies are looking to upgrade the look as far as lights and add lofts, nicer seats, those types of things."

Apart from aesthetics, agencies also want to stand out. When the time comes to update fleets, operations want vehicles that look unique.

To accomplish these upgrades and style requests, lighting manufacturers work hand-in-hand with vehicle OEMs and agencies to develop a custom application. Pretoria's combination of anodized aluminum extrusions and composite panels, standard on all its models, can be customized to fit any design requirements specified.

Manufacturers have designed lights integrated into parcel racks and air ducts so systems resemble motorcoach applications in functionality and design. Keeping with transit bus tradition, lighting coves can be equipped with advertiser card space.

Operators can also request various shaded sleeves to enhance or dim lights or to provide more life to the bus. Brightly colored sleeves could be used by university transportation agencies to show school support.

Innovation and improvement
In the swamp of new regulations posed by federal safety agencies, lighting providers have still managed to improve their products. Significant design improvement and new products stem from agency demands and complaints, and companies are designing applications to match desires.

There has also been innovation and regulation reform for lighting on smaller buses. Buses under 30 feet in length have different requirements than larger city buses.

"What you find in the market is many of the small buses are used for special routes," says Transmatic's Longanbach. "We've been working with the industry to promote higher standards in those because if something were to occur on the bus, you want to make sure the driver can get to the problem."

Innovations in vehicle development also go far beyond improving standards. Newer transit vehicles have updated lighting systems. For example, Pretoria is working with OEMs to design fixtures for BRT vehicles. New Flyer's Invero bus, for example, offers Pretoria interior lights that reduce window glare for passengers.