The concept of individual mobility budgets introduces a yearly upper CO2 emission limit for individual travelling (a “ceiling”). However, it is equally important to establish a minimum lower limit (“floor”) to ensure equitable and fair access to activities in other locations within a population.
A minimum mobility standard serves as an allocation principle providing fairness. It guarantees that everyone can reach the nearest locations for pursuing important activities in everyday life within reasonable time. The minimum standard accounts for personal circumstances, granting everyone the right to reach the nearest relevant destinations, regardless of the place of residence or personal abilities.
But how can a minimum mobility standard be defined? The approach taken by the MyFairShare project relies on three factors that constitute a potential “right to mobility” and perhaps even a basic human right.
- Constant travel time budget: Studies in human geography consistently show that people tend to spend an average of 60 to 80 minutes per day traveling, as a kind of ‘natural’ behaviour. This observation, initially made by Marchetti (1994), challenges the common assumption that reducing travel times always leads to economic benefits. Instead, investments in time-saving infrastructure often result in people traveling longer distances rather than reducing travel time.
- Activity spaces: The second factor on which MyFairShare bases a minimum mobility standard are activity spaces. Activity spaces refer to locations that people visit daily to fulfil basic functions of everyday life. These are, for example, home, the workplace, and recreational spaces. Activity spaces define how often an activity needs to be accessed within a time period, e.g., per week.
- Lowest possible transport emission factor: Different transport modes are responsible for various levels of CO2 emissions per person-kilometre, which also include emissions related to the production of vehicles and energy. Therefore, the emission factors associated with each mode are considered when calculating the minimum standard.
Based on the three factors explained above, the minimum mobility standard is defined as the minimum amount of CO2 emissions that allows a person to reach three to four of the nearest places providing basic functions of everyday life within up to 80 minutes of travel per day. This standard does not consider personal preferences but focuses on the closest opportunities for essential functions. Personal preferences can be satisfied using the allowances beyond the minimum standard within a person’s individual mobility budget.
The minimum mobility standard defines an individual’s eligible minimum mobility budget, which in turn varies from person to person depending on individual factors such as location of residence and transport restrictions that may arise with age or physical condition. Individuals who can reach all types of basic functionalities within 80 minutes by walking, for example, do not require a minimum mobility budget, but receive their share of the remaining emission budget beyond minimum budgets. If it is not possible to reach the closest places providing basic functionalities within the defined lowest standard, a person’s minimum mobility budget is increased to allow for the use of the next higher carbon-intensive mode of transport and so on, until it is possible for a person to fulfil their basic needs.
Complementary policy and planning measures shall over time enable for everyone to achieve the smallest individual mobility budget possible, thereby aiding in achieving emission reduction targets while still providing for each person’s daily mobility needs.
- Marchetti, C. 1994. “Anthropological Invariants in Travel Behavior.” Technological Forecasting and Social Change 47 (1): 75–88.