Accessibility analysis

Accessibility analysis is a powerful tool for planners, to assess how mobility measures enable people to travel to various destinations. By using accessibility analysis, planners get deep understanding of what works, and what are the barriers to better connectivity.

What is accessibility?

Accessibility is a mobility indicator of the possibilities and limitations for people to move from A to B. That means, how they can reach places of employment and education, parks, and other destinations, by all means of transport – walking, public transit, private vehicles, or cycling.

Instead of predicting what people will do, accessibility measures what they can do. This information helps to understand the existing mobility systems and can be used to compare the impacts of projects and changes.

This means that accessibility does not only relate to the qualities of the transport system (e.g., travel speed, time or costs), but also to the qualities of the land use system (e.g., density and mixes of opportunities). It thus provides planners with the possibility to understand the interdependencies between transport and land use development.

Accessibility planning opens the floor to a more normative approach to transportation planning involving different actors. For politicians, citizens and firms it might be easier to discuss the quality of access to education, services and markets than it is to discuss the inefficiencies of the transport system itself. Accessibility is also defined as "the potential for interaction".

In the example on the left side, there is an accessibility map of Germany’s capital city Berlin. It focuses on accessibility by public transport to workplaces. The map shows the share of workplaces that residents of each area can reach within 30 minutes by using public transit.

What is an accessibility analysis?

The accessibility of locations is an indicator when assessing or evaluating mobility concepts. Therefore, accessibility analysis is an important instrument in transport planning, provision of public services, and location planning, evaluation, and optimization.

There are different indicators that define accessibility, depending on the use case. For example, to analyze the accessibility of a planned kindergarten, it is more relevant to measure pedestrian accessibility for children in the vicinity. But when planning a logistics distribution center, it is more important to measure accessibility for trucks or for the recipients of the goods.

When the metrics of an accessibility analysis are visualized, planners get an additional perspective for considering connectivity, especially for biking, walking, and transit. This helps them understand the transportation situation.

Accessibility data with high spatial resolution clearly show areas where mobility provision does not match mobility needs, e.g., which are underserved by public transport. As a result, it is possible to quantify the improvements and investments needed.

By analyzing land use, road infrastructure, traffic stress, and transit schedules, stakeholders can analyze the mobility networks and how they enable people to travel to various destinations. This gives planners an understanding of what works, and of barriers to better connectivity.