Pedestrian Lighting

Introduction
“Pedestrian lighting” includes all exterior lighting applications where people travel by foot or on bike along pathways, walkways, bikeways and roadways. As such it is an application within the larger discipline known as outdoor lighting, and intersects with roadway and landscape lighting at times.

Broadly speaking, pedestrian lighting falls into one of three categories:

• When it is the only lighting present and must do all of the lighting tasks (security, hazards, wayfinding and decorative)

• When it is part of a larger lighting system and is used as a beacon or supplemental lighting for wayfinding and other hazards

• When the “pedestrian lights” are low power and used primarily for decorative purposes while another system performs all other lighting functions

In all cases, the overall lighting system must enable pedestrians to navigate the path as safely and securely as possible.

The issues that must be considered with outdoor lighting also apply to pedestrian lighting, such as vandalism, maintenance, foliage and trees, weather, and safety and security.

Walkways
Walkways and bikeways may be part of a roadway and addressed as part of the roadway lighting design, or they may be independent pathways. Our primary goal is to provide sufficient maintained light levels on both the horizontal and vertical planes and provide uniformity to ensure visual comfort, visibility and safety. Major factors to be considered in a pedestrian lighting application include:

Hazard:
The hazard level for an area, sometimes called “conflict,” refers to the level of traffic and security risk that is present in the pedestrian zone. A high-hazard area would be a roadway that vehicles and pedestrians share; where many pedestrians are present; or where special safety and security risks are present in the environment. The higher the hazard level, the greater the light levels that are required. Hazard also determines the workplane. For typical applications, the average horizontal light level should be at grade. For applications that pose special security considerations, the average vertical light level should be at 5 ft. above grade (about “head height” for average adults while walking). Be sure to check local and other applicable lighting codes to ensure compliance with light level requirements that may be mandated by law.

Aesthetics:
In many areas, pedestrian lighting can contribute to the ambience of the environment not just in the patterns and distribution of the light, but also through the appearance of the fixtures themselves (see Figure 1). The designer may also want the fixtures to integrate with the landscape and be largely unnoticed. In other cases, creative deployment of decorative luminous elements can make pathway lighting more magical. For example, fiber-optic strands can be built into pavement materials, creating tiny sparkling lights on a path, or used in Victorian-style post-top fixtures in a historic part of town.

Roadways
Roadway lighting is a significant area within outdoor lighting and often intersects with walkway lighting, providing light for people on sidewalks, crossing the street, etc. The IESNA offers RP-8, Roadway Lighting, to provide calculations and recommended practices. For freeways, expressways, major roads, collector roads and local roads, average maintained light level recommendations are provided that in turn are based on the level of pedestrian traffic (high, medium, low) and the type of pavement in use. Each type of pavement, such as concrete and asphalt, has particular reflectance characteristics that in turn affect the light level recommended. The IESNA also recommends maximum uniformity ratios and brightness ratios. Note that various municipalities may require different average maintained light levels on roads. Tacoma, WA, for example, requires a minimum of 5 fc while Northville, MI, requires 1 fc. Be sure to check with municipal, county and other applicable codes and ensure that the design conforms to all appropriate ordinances. Also ensure that the fixtures adhere strictly to local codes and common concerns regarding light trespass and light pollution.

The city “streetscape” can include up to four layers of lighting:

High-Mount:
These fixtures, typically 20-30 ft. in height, are used to provide uniform minimum light levels for the street and sidewalk. Designed to blend in with the background, these fixtures are of the cut-off type: Light output at 90° above nadir is less than 2.5% of rated light output, and light output at 80 is less than 10% of rated light output. (“Nadir” is the angle equal to zero degrees, oriented vertically downward.) The maximum average-to-minimum light level ratio is 3:1 to 4:1, providing what most often appears to be uniform lighting across the street.

Medium-Mount:
These fixtures, typically pole fixtures 8-15 ft. in height, are used to provide additional lighting to sidewalk areas. Due to their lower mounting height, glare becomes a concern, commonly resulting in utilization of lower-wattage lamps and louver assemblies that shield the lamp and distribute the light diffusely. As a result of their light output and lower height, they are spaced closer together to ensure uniformity of light distribution. These fixtures are often more visible to pedestrians and therefore decorative, designed to fit into the city’s image. A city that wants a high-tech appearance for its downtown, for example, can choose fixtures that support this image, while a city that wants to project a more quaint or rustic image can choose decorate or antique-style fixtures. Globes and similar omni-directional fixtures with poor optical control should be avoided as they are inefficient and contribute to light pollution and light trespass. However, if used sparingly and with low-wattage lamps, they can produce a pleasing glow, adding an aesthetic element to the lightscape.

Low-Mount:
These fixtures include bollards and similar small outdoor fixtures that illuminate items of interest on the street. For example, a fixture may include signage or it may be located near an area where caution should be shown or where there is something that should be given pedestrian attention. These fixtures can be decorative or purely functional, as in the case of integrating signage and lighting.

Focal Points:
Special lighting may be used for public works of art or other areas of special visual interest. These objects require a higher light level to attract attention. Lighting may be uplighting, downlighting, bollards or other types, and the light itself may be colored.

Choosing The Right Solution
The best pedestrian lighting solutions are:

• Energy-efficient

• Rugged and durable

• Provide sufficient quantity and quality of light for pedestrians to walk safely

• Do not produce light pollution or light trespass

Above: Pedestrian Lighting on the NE 90th Street Bridge in Redmond, WA

Image courtesy LMN Architects and Sidney Genette