Global Street Design Guide Resources Key Terms

Global Street Design Guide

Key Terms

Active Frontage

Active Frontage refers to the street frontages or edges that allow a visual or physical engagement between the street users and the ground floors of buildings. Frequent openings and windows with few blank walls; narrow-frontage buildings that give vertical rhythm to the street edge; facade articulation; transparency that promotes eyes on the street; and uses spilling onto the street contribute to active frontages. Making building edges “active” to the street adds interest and vitality to the street environment.

Active Mobility

Active Mobility or healthy transportation choices, refers to any form of human-powered transportation. These may include walking, cycling, or using a non-mechanized wheelchair that increases physical activity levels, positively impacting public health. All active modes of transportation are also sustainable modes of transportation as they leave minimal carbon footprint and do not contribute to carbon emissions.

Clear Paths

The pedestrian clear path defines the primary, dedicated, and accessible pathway on the street. It is an unobstructed, level, and smooth surface that ensures that pedestrians have a safe and adequate place to walk. Clear paths must be wide enough to allow two people in wheelchairs to pass one another, and are recommended to have a minimum width of 1.8 m.

Daylighting (Intersection)

In intersection design, Daylighting consists of prohibiting parking and loading within a certain distance of an intersection to increase visibility between motorists and pedestrians. This can also be achieved through geometric design, by physically extending the curb, or raising the pedestrian crossing. Temporary or permanent bollards are often used to daylight intersections in low-compliance contexts.

Deflection

Vertical Deflection: It refers to speed control measures which involve the modification of the pavement elevation. When well designed, vertical deflection measures self-enforce slower speeds for motorists. Examples include speed humps, speed cushions, speed tables, and raised crossings.

Horizontal Deflection: Horizontal speed control measures cause motorists to slow down in response to either a visually narrower roadway or a need to navigate a curving travel lane. Examples include curb extensions, pinch-points or gateways, chicanes, and lane and roadway narrowing that might result from the introduction of medians or pedestrian refuge islands.

Dooring

When a passing cyclist is struck by the sudden opening of a vehicular door in the door zone of a parked vehicle, it is referred to as Dooring.

Exposure and Risk

For the purpose of this guide, Exposure is defined as the state of being exposed to risk. It is measured as the probability of a user being involved in a crash. Risk refers to any situation involving exposure to danger, injury, or loss that may involve factors such as perception, willingness, and convenience. Mathematically, it is defined as injury rate calculated as the number of injuries or crashes over the amount of exposure, or over the population. Risk may apply to perception of risk or the tendency to take risk.

Facilities ( Cycle or Transit)

Facilities, such as cycle facilities or transit facilities, are designated spaces within the street that are specifically designed for the movement of the given mode. Dedicated facilities ensure safe and efficient movement of the mode.

Green Infrastructure

Green Infrastructure is a planning and design approach to managing stormwater and other natural resources to create healthier environments. The term describes the network of green spaces and water systems that mimic those found in nature and values their ability to deliver multiple environmental, economic, and social benefits.

Infrastructure (Pedestrian, Cycle, or Transit)

Infrastructure refers to all facilities and amenities that may be used by the person using a given mode of transport. For example, in the case of pedestrians, it may refer to sidewalks, accessibility ramps,or benches, while in the case of cyclists, it may refer to cycle facilities, bike racks, parking, bike signals etc.

Interim Designs

Interim design strategies are a set of tools and tactics that cities can use to improve their roadways and public spaces in the near term. They include low-cost, interim materials; new public amenities, and creative partnerships with local stakeholders, which together enable faster project delivery, and more flexible and responsive design.

KSI or Road Traffic Fatalities

KSI stands for Killed or Seriously Injured and the definition may vary from country to country. For the purpose of this guide, seriously injured refers to a non-fatal injury received due to a crash which prevents the person from walking, driving, or normally continuing the activities the person was capable of performing before the injury occurred. Killed refers to road traffic fatalities, where the person dies within 30 days after collision due to injuries received in a crash. Road Traffic Fatalities refers to both Killed and Seriously Injured.

Mixed Traffic

The flow of traffic in which users and vehicles with different operating speeds and purpose are mixed without physical separation is referred to as Mixed Traffic.

Mode Share

Mode Share is also called mode split, modal share, or modal split. It is the share or the percentage of commuters using a particular type of transportation or number of trips using a type.

Roadway or Roadbed

Roadway, also known as roadbed or carriage way, is the part of a street is intended for vehicular movement, in contrast to a sidewalk or median. Often referred to as the curb-to-curb distance, it can be measured from one edge of the curb to the other.

Street Capacity

For the purpose of this guide, Street Capacity refers to the volume of people or total number of persons that a street can move in the given space and time, using any mode of transport.

Sustainable Modes

As the name suggests, any form of transport that is sustainable with respect to social, environmental, and climate impacts is a sustainable mode of transport. These modes do not use or rely on depleted natural resources. Instead, they rely on renewable or regenerated energy. This form of transport is socially equitable and offers increased mobility. This guide considers all active modes of transportation, collective transportation, along with vehicles using renewable energy, as sustainable modes of transportation.

Target Speeds

Target Speed is the fastest speed any user should travel; it should be determined based on the need of the users and context of the street and used as the design speed that, in turn, informs the posted speed limit. A proactive approach selects a Target Speed, and uses design to achieve that speed, guiding driver behavior through physical and perceptual cues.

Traffic Calming

Use of physical design and other measures, including narrowed roads and vertical or horizontal deflections, with the intention of slowing down or reducing motor-vehicle traffic and speed to improve safety for pedestrians and cyclists is known Traffic Calming.

Vulnerable Users

While all road users are at risk of being injured or killed in a road traffic crash, there are notable differences in fatality rates between different user groups. In particular, the Vulnerable Users such as pedestrians, cyclists, and motorized two-wheeler users are at greater risk than vehicle occupants and usually bear the greatest burden of injury. However, under the category of pedestrians, children, seniors, and people with disabilities are particularly vulnerable, as their physical and mental skills are either not fully developed or diminished.

Universal Accessibility

Universal Accessibility, in context of this guide, builds upon the principles of universal design. It refers to design that includes the needs of people whose physical, mental, or environmental conditions limit their performance. It aims to extend its definition to include people of all ages and abilities, who might be in a temporary situation of handicap at a given point. It addresses the larger issues of usability and access by making navigation and movement easier for everyone.

Adapted by Global Street Design Guide published by Island Press.