Defining Accessibility and Mobility in Transportation and Geography

Truck and highway at sunset
dell640 / Getty Images

Accessibility is defined as the ability to reach a place with respect to another place. In this context, accessibility refers to the ease of reaching destinations. People who are in locations that are more accessible will be able to reach activities and destinations faster than those in inaccessible locations. The latter will be unable to reach the same amount of locations in a certain period of time.

Accessibility determines equal access and opportunity. The public transport accessibility level (PTAL) in the United Kingdom, for example, is a method of transport planning that determines the access level of geographical locations in regards to public transportation.

Mobility and Accessibility

Mobility is the ability to move or be moved freely and easily. Mobility can be thought of in terms of being able to move throughout various levels in society or employment, for example. While mobility focuses on moving people and goods to and from various locations, accessibility is an approach or entrance that is either obtainable or attained. Both forms of transportation modes rely on each other in some way, depending on the scenario, but remain separate entities.

A great example of improving accessibility, rather than mobility, is in the case of a rural transport scenario where water supply is needed at houses far away from the source.

Rather than forcing women to travel long distances to gather water (mobility), bringing services to or closer to them is a more efficient effort (accessibility). Distinguishing between the two is critical in creating a sustainable transportation policy, for instance. This type of policy may include a sustainable transportation system which is also referred to as Green Transport and considers, social, environmental, and climate impacts.

Transportation Accessibility and Geography

Accessibility in regards to geography is an important element in mobility for people, freight, or information. Mobility is determined by people and affects infrastructure, transport policies, and regional development. Transportation systems that offer better opportunities of accessibility are considered well-developed and efficient and have a cause and effect relationship to various social and economic options.

Capacity and arrangement of various transportation options largely determine accessibility, and locations range in terms of equality due to their level of accessibility. The two main components of accessibility in transportation and geography are location and distance.

Spatial Analysis: Measuring Location and Distance

Spatial analysis is a geographical examination that looks to understand patterns in human behavior and its spatial articulation in mathematical and geometry (known as locational analysis.) Resources in spatial analysis typically surround the development of networks and urban systems, landscapes, and geo-computation, a new field of research to understand spatial data analysis.

In measuring transportation, the ultimate goal is typically around access, so that people can freely reach their desired goods, services, and activities.

Decisions around transportations typically include tradeoffs with different types of access, and how it is measured affects larger impacts. To measure transportation system data, there are three approaches some policymakers use, including traffic-based measurements, mobility-based ones, and accessibility-based data. These methods range from tracking vehicle trips and traffic speed to traffic time and general travel costs.

Sources:

1. Dr. Jean-Paul Rodrigue, The Geography of Transport Systems, Fourth Edition (2017), New York: Routledge, 440 pages.
2. Geographic Information Systems/Science: Spatial Analysis & Modelling, Dartmouth College Library Research Guides.
3. Todd Litman. Measuring Transportation: Traffic, Mobility, and Accessibility. Victoria Transport Policy Institute.
4. Paul Barter. The SUSTRAN mailing list.