Gap points shall describe the value of the real damage and danger a vehicle causes: to health, to life, to the climate, to the street and to the space everyone shares. Determining how many points each feature of a vehicle and each kind of use carries is still to be done. It is the task of the two previous chapters, vehicle damage and harm assessment and vehicle use assessment.
This chapter explains what happens once the points are known: how they add up, and how they become a price per kilometre. That price is the full cost a vehicle causes to society. How much of it drivers are asked to pay is a separate decision, set out in road user charge.
what a gap point stands for
As a working definition:
1 gap point = 1 cent of cost to society per kilometre
This makes points comparable across very different kinds of harm: a gram of particulates, a tonne of extra mass, a poor view from the cab. All are expressed in the same unit, so they can be added up.
adding up the points
A vehicle’s total comes from two sources:
- what the vehicle is: mass, footprint, speed and acceleration capability, direct vision, protection of people walking and cycling, emissions, noise
- how and where it is used: time, place, occupancy, sensitive zones such as school streets, and whether a public alternative exists
How the two combine is still open. The likely form is that use works as a factor on the vehicle’s points: the same vehicle causes more harm in a dense neighbourhood at rush hour than on an empty road at night. Part of the rating already works this way, because speed capability multiplies the points for mass. Whether a total cap applies is also still to be decided.
from points to price
Once the points are added up, the full cost follows directly:
gap points × 1 cent = cost to society per kilometre
A vehicle with 60 gap points causes about 0,60 € of cost to society per kilometre. Driven 10 000 km a year, that is about 6 000 €.
A vehicle at zero, such as a bicycle or a light electric vehicle within the limits of Baseline 0, causes no cost in this sense and has nothing to pay.
checking the result against the real costs
The points have to add up to the costs that actually arise. Across the whole fleet, all points multiplied by all kilometres driven shall reproduce the total cost set out in costs of our streets and external costs of passive mobility. If they do not, the weighting is wrong, not the costs.
Two independent estimates already give the order of magnitude. A calculation by Green City e.V. for Munich puts the hidden public cost at roughly 0,60 € per car kilometre. A 2026 global study puts the cost borne by others at about 0,55 USD per car kilometre (Schweiggart, Gössling, Nieuwenhuijsen, Creutzig 2026). Different methods, different geographies, the same order of magnitude. An average car should therefore end up at around 60 gap points.
What these figures can and cannot show. A single figure per kilometre says nothing about the individual vehicle: 0,60 € for “a car” captures nothing of mass, footprint, direct vision or acceleration. It is the average the rating has to reproduce across the fleet, not the rating itself.
A second Munich calculation, with the tool developed at the University of Kassel, puts the external cost per trip at roughly 0,36 € by car, 0,105 € by bicycle, 0,044 € by public transport and 0,025 € on foot. These figures cannot be combined with the per-kilometre figure: they draw different boundaries around which costs are counted. What they do show reliably is the ratio: a car trip costs roughly eight times a public transport trip and fourteen times a walk.
the calculation model
A transparent calculation model, in the form of a spreadsheet, turns the points into figures for a given city. For each vehicle type it shows the full cost per kilometre and per year. Combined with the share a city decides to charge, it shows the revenue raised, how the burden falls by household type, income and place, and what remains public subsidy.
Because it is transparent, every city can run it with its own data and political choices, and every driver can see how their figure is calculated and which steps would reduce it.
The economic side of this work still needs partners. Researchers in this field are welcome to get in touch.
what is still open
- the weighting: how many points each feature and each use carries, derived from damage costs per unit
- a common scale across cars, two-wheelers and commercial vehicles, based on real-world emissions and not on the name of an emission standard
- the combination rule: how vehicle and use points come together, and whether a cap applies
- the boundary: which costs are counted, without counting any twice
Schweiggart, N., Gössling, S., Nieuwenhuijsen, M., Creutzig, F. (2026): The global cost of automobility. Transportation Research Part A 214, 105235. Open access