LED Lights for Tunnels
Shop the 5+ year warranty-backed LED tunnel lighting systems that are improving safety in roadway & railway tunnels and underpasses while using 75% less energy.
Tunnels for cars, pedestrians, or bikes all require proper lighting for good safety and security. LED tunnel lights provide both along with tremendous energy savings.
LED Tunnel Fixtures
LED Tunnel Lighting
When driving in many tunnels, the words "dark and dingy" are the first ones that come to mind to appropriately describe the passages. They are poorly illuminated and one gets the feeling that an accident can happen at any given time. This is why when you see a tunnel that is well illuminated, you may ask yourself "why are all tunnels not well lit?"
LED lighting has shown us that tunnels, just like exterior spaces, can be brightly illuminated at all times. In fact, tunnels that are lit by LEDs help drivers’ eyes to adjust easily and quickly. The passages do not experience disruptive maintenance from time to time and their energy usage is low – although their light quality is much better.
One of the biggest challenges of tunnel and underpass lighting is the capability to support drivers’ visual acuity during the day and night – from the entry point to the exit point. Good tunnel lighting creates consistent light levels throughout the tunnel for safe passage.
Tunnels happen to be highly corrosive environments that require highly durable luminaires that are also sealed. Because of heavy traffic and changes in climate and weather, the light fixtures used are frequently exposed to exhaust fumes, brake dust, dirt, water, road salt, and other highly corrosive elements.
LED tunnel lighting is the best lighting option for tunnels. To begin with, the lights have a power efficiency of 75% or more, meaning they use 75% less energy than traditional lights. Secondly, their shortest lifespan is 50,000 hours. High-quality LED tunnel lights can function for up to 100,000 hours.
Some of the LED lights used in tunnels have a beam angle with a horizontal axis of 100° and a vertical axis of 90°. The luminaires distribute light using a beam pattern and their input voltage is AC 85-264V or AC 85-277V.
Advanced technologies and materials are used in the manufacture of LED tunnel lights. Manufacturers use such measures because LED lighting is nothing like normal road lighting. For example, tunnel lighting can be easily affected by environmental conditions such as vibrations, loud noises, and vehicle exhaust fumes.
It is important for manufacturers of tunnel lights to discuss the design of the tunnel (for new tunnels) in order to create the best lighting system that will make the structure safe for drivers, pedestrians, and even cyclists.
Determining Illumination Levels for Tunnels
If a tunnel’s total length is 736 meters, it may be divided into 3 illumination areas for lighting purposes. The brightest area is the area between the entrance to 30 meters inwards. A total of 80 lux is needed in this area for adequate illumination.
The area next to the brightest area (30-60 meters inwards) is the medium bright area and requires about 50 lux. 40 lux may be needed in the area after that (60-96 metres inwards) which is known as the transition area. The middle of the tunnel does not require very bright light, approximately 30 lux for illumination.
In a tunnel of this size, only 143 luminaires may be needed for the whole structure. 40 units can be used at the entrance and at the exit of the tunnel, bringing the total to 80, and the remaining 63 pieces can be installed in the middle of the tunnel. The lights can be paired with intelligent lighting controls that adjust their brightness as per the amount of natural light available.
It is worth noting that the design of a tunnel will be the biggest determinant of the lighting fixtures required since not all tunnels are straight. Special tunnel lights can also be manufactured to meet your specific requirements.
Zones of Tunnel Lighting
The International Commission on Illumination (CIE), a governing body on the art and science of lighting, has a publication on tunnel lighting (CIE 88-1990). The publication states that the quantity of light required in a tunnel is directly dependent on the available natural light outside the tunnel and also the point in the tunnel where the user's visual adaptation must occur.
When it comes to planning the lighting design of a tunnel, there are 5 important areas to consider.
This area is not found within the tunnel, it is actually the stretch of road that leads to the tunnel’s entrance. When at this zone, drivers must be able to see the tunnel’s interior and detect any possible obstacles. They must be able to drive easily into the tunnel without reducing their speed.
The capacity of the driver to adapt in the access zone dictates the lighting level in the subsequent part of the tunnel. One method used by the International Commission on Illumination to compute visual adaptation is the L20 method. The method takes into consideration the median luminance from the road, sky, and the environment in a cone of 20° centered on the driver's line of sight from the start of the access zone.
This is the part of the tunnel that is visible before a driver drives into the tunnel. The length of this zone is equal to the stopping distance. The required luminance for the first part of this zone must always remain constant as it is linked to the luminance for the exterior (L20) as well as traffic conditions. At the end of the threshold zone, the luminance level should be decreased to 40% of the value.
This zone comes after the threshold zone and is where the luminance level goes down to the level in the inner zone. The luminance in this zone is necessary for drivers to be able to see the stopping length in front from any point in the transition zone and the threshold zone.
Over the distance of this zone, the luminance is decreased progressively to attain the level in the inner zone. The decrease stages should not surpass a ratio of 1:3 because they are connected to the capability of the human eyes to adapt to the environment, and are therefore time-related. The transition zone comes to an end when the luminance of the zone is equivalent to 3 times that of the interior level.
This inner zone is located between the transition zone and the exit zone. The luminance in this zone is vital for an enhanced level of traffic safety inside the tunnel by day.
The interior zone is usually the longest stretch of the tunnel and the lighting levels in the zone are connected to the speed and density of traffic.
This is the last part of the tunnel where the eyes begin to acclimatize to the outdoor lighting level. The lighting fixtures used here must not create a big contrast between luminance in the tunnel and the luminance in the exterior. During the day, the vision of a driver drawing nearer to the exit is affected by the brightness outside of the tunnel.
Since the human eye can adjust almost instantly from low to high lighting levels, the processes that apply when entering the tunnel are not reversed. But reinforced lighting may be needed in some instances where lighting contrast is required in front or behind the driver if the exit is not visible, if the exit serves as an entrance, in case of emergency, or when maintenance works are ongoing and one part of a twin tunnel is closed. The maximum length of this zone is 50 meters and the light level must be five times that of the interior zone.
Comparing LED Tunnel Lighting to HID Lighting
Up to today, traditional light sources such as metal halide and high-pressure sodium are still used in tunnels. And while both lighting systems offer tunnel lighting designers a good combination of proven mechanical construction, high illuminance and low unit cost, each of these luminaires can draw up to 400 watts to meet the illuminance requirements.
Tunnel lighting schemes need a high illuminance to create a safe environment for drivers. The lights must be able to deliver high levels of light a good distance from the plane. The standard mounting height in road tunnels is 16.4ft to 23.0ft in order to provide clearance for high-sided vehicles.
The shortcomings of high pressure sodium and metal halide luminaires are many. To start with, they use a high amount of energy and deliver a low quality of light. They do not provide consistent and uniform lighting in the tunnel and frequently experience catastrophic failures that call for costly maintenance to remedy.
LED technology keeps on advancing and tunnel operators now have a lighting alternative that is appealing from both the operational and public perspectives. The most obvious advantages of LED tunnel lights are efficiency and a long lifespan.
LEDs, which are highly reliable semiconductor devices, have very long useful lives. Their long lifespan significantly reduces lighting maintenance costs, traffic disruptions caused by closures because of maintenance, and poor lighting because of lamp burnout.
LEDs are also capable of delivering more than 100 lumens per watt in tunnel lighting applications. Since they are directional point sources, their light can be precisely delivered to the target areas. For this reason, they have a higher system efficacy compared to high intensity discharge lamps.
LED tunnel lights allow for increased light control in the entrance and exit zones where drivers attain proper eye adaptation between the exterior environment and the interior of the tunnel. High pressure sodium and metal halide lights used in the entrances of tunnels are usually designed to replicate the light levels of full sunlight during the brightest part of the day. Some sections of this luminaires are switched off during the day, depending on the exterior light levels.
However, when the light output of HID lighting is matched to the exterior light levels, the result is usually over-illumination during the day. The light produced by high intensity discharge lights is also a poorer match compared to the required light level.
The biggest reason the lighting is inferior is because HID light levels cannot be accurately controlled. On the contrary, LED tunnel lights are fully dimmable and accurately match the required lighting levels, getting rid of the issue of over-illumination and drastically reducing energy consumption.
Because LEDs are so well built and do not fail catastrophically like high pressure sodium or metal halide lamps, there's never a need to shut down a part of the tunnel, put up high-level platforms, and carry out relamping tasks to maintain public safety. This does away with a huge nuisance for the public, ensures tunnel lanes stay open, and traffic smoothly flows in the tunnel.
Solid State Lighting Technology Delivers Quality Lighting
As LED technology has advanced, its applications have also increased. Tunnel operators are now in favor of using LED products in tunnels. LED lights offer superior color rendering, unlike common alternatives for tunnel lighting such as HPS and MH lamps.
When it comes to tunnel lighting, both visual perception and total cost of ownership are important factors to consider. Since tunnels are usually built by municipalities, achieving a lower lifetime cost is necessary because any installation is paid for out of limited tax and toll revenues – given the state of public funding.
Thankfully, the latest advancements in LED technology have drastically reduced the purchase and electrical costs of LED lighting systems to the extent that they offer a considerably lower lifetime cost than other lighting systems.
LEDs are able to create a superior lit environment in two ways: an increased quality of light and decreased impact on traffic flow. One of the reasons they have a superior quality of light is because of their excellent color rendering. Most of the LED lights used in tunnels have a color rendering index of 80 and above and produce a more natural-looking environment than HPS or MH lamps.
With true rendering of colors across the spectrum, they help drivers to differentiate objects in the distance better. They make an environment feel safer and provide uniform lighting throughout the tunnel.
The lenses of LED lights, which are created using advanced optical modeling tools, offer a uniform light pattern in the tunnel with neither shadows nor distracting glare. This uniformity in lighting is possible as LED lights are comprised of arrays of powerful, tiny LED chips with unique beam patterns that can be shaped as required. For instance, total internal reflection lenses on each LED chip help create the desired beam.
Types of LED Tunnel Lighting
Canopy lighting is outdoor lighting used to light up areas that are usually frequented by drivers and pedestrians. These lights are very popular in industrial applications and used to illuminate aisles and walkways. The most unique thing about these lights is that they are perfect for areas where the light of the sun does not reach. They are also used to illuminate areas that are used at night and also in buildings without windows.
LED canopy-lights are excellent replacements for HID and fluorescent tunnel lights as they are more efficient and have a longer life expectancy. They are also easier to install and need less maintenance. They make tunnel entrances and exits safe at night and also provide a clean, modern look.
Linear fixtures are perfect for long spaces such as large rooms or hallways. There are 2 ft, 4 ft, and 8 ft-long fixtures that are waterproof and ideal for use in wet, dusty, and damp commercial spaces.
These lights can also have high impact, frosted or clear lenses to enhance their lumen output. LEDs mounted on linear strip fixtures are very ideal for overhead task lighting and can be used in canopies, hospitals, cold rooms, car washes, tunnels, and the outdoors where water and dust pose a challenge to traditional lighting modes.
LED-HID retrofit kits are manufactured to easily replace high pressure sodium and metal halide bulbs. They maintain the look of the existing fixtures while offering the benefit of lower utility cost. Retrofit-kits are available in a myriad of color temperatures and wattages. Most applications use color temperatures between 5000K-5500K as they are much brighter and have a pure daylight white color.
These highly economic lighting sources fit inside traditional lighting fixtures and provide great energy savings while increasing lighting levels. Some LED-HID replacement bulbs are built to replace specific HPS or MH lamps, depending on the wattage. Because HID lamps require a lot of power to produce enough light, they drive up the lighting electric bill. Replacing these lamps with LEDs offers a more effective lighting solution.
For tunnels with fluorescent lamps, LED magnetic-strip light kits are the best choice. Most of the kits have an LED driver with magnetic backing and 2, 3, or 4 light strips. Some kits have frosted lenses that diffuse the light and make the strips look like fluorescent tubes.
Magnetic-strip light kits have one big advantage over LED tube lights, they run a little more efficiently. Enhanced efficiency means you enjoy more light out of every watt. Strips are also quicker to install because power is only wired to the driver. Most magnetic-strip light kits are rated for 50,000 operating hours. This means that if the lights are used for 12 hours a day, they will last almost 12 years.