Automated Measure to Reduce Usage of Privately Owned Cars in Cities
The premise of personal mobility from the 1950s onwards has been the individually owned car in order to realise an unconstrained freedom to go anywhere, any time. Cities were consequently designed for and around cars with sub-urban sprawl as a consequence, too. Now mankind realises that there are a few issues with that assumption. First, the approach is not scalable: if everybody exercises the freedom to go anywhere any time by car, limitations to this very freedom ensue in the form of traffic jams; the result is much less freedom. Second, the approach is not sustainable given the energy needs and carbon emissions, in particular for large vehicles competing for space and resources.
That being said, the situation has to be rectified, possibly with market forces installed in order to reinstate a balance, take externalities into account, reduce the number of cars and eventually, through human-friendly urban planning, reduce the number of miles travelled. Here I would like to propose a metric and an automated mechanism for a levy on vehicles in urban environments as an incentive to reduce the usage of those privately owned cars in cities. This measure is the feed-back mechanism of a free market by attributing cost for the usage of public goods to the users. This system would be introduced gradually with the objective to shift the use of cars to shared mobility and multi-modal transports, including cycle path networks and public forms of transport such as trains, trams and buses. The revenue from that levy can be used towards those goals.
Vehicle usage tax
The metric presented here includes three factors: one based on vehicle mass, one on vehicle extent and one on the presence fraction of the day. As for the first one, it is well known that the damage to the road is related to the weight of vehicles, the fourth power law. For instance, a vehicle twice as heavy causes 16 times more damage. Vehicle users should have to contribute to the up-keep, repair and maintenance commensurate with the vehicle weight. The second factor is related to the volume, or extent, of the vehicle in two ways: the footprint which is more a issue with parking and other situations and the cross section which reduces visibility of other traffic participants (cyclists). Third, the levy is proportional to the fractional presence per day, i.e. number of hours divided by 24, e.g. half the presence per day, half the levy. All combined yields a metric which can be used to calculate a vehicle levy as a product of the vehicle mass and extent factor, both as a ratio to a reference, and the fractional presence, together with some “gain” to adjust the levy in the appropriate currency:
The reference mass and volume can be obtained from a statistical distribution, e.g. the median or 25 percentile. A reasonable reference for me as a European is a Volkswagen Golf with around 1200kg and 11 cubic meter extent.
Note, that here I did not include the energy consumption or carbon emission as I think they are proportional to the fuel consumption; for vehicles powered by fossil fuels a tax should be levied at the pump or upstream, as it is currently the case.
Further note that the number of occupants is not reflected in the levy. Only by sharing a vehicle and spreading the cost will the individual contribution decrease. Consequently, driver larger vehicles into town only makes sense if they are fully occupied.
Automated invoice mechanism
Now to the automated mechanism to enforce the levy on vehicles. The general idea is that the tax is due for every day the vehicle travels in the urban environment, calculated based on the presence of the vehicle on the road network within a day as a fraction as well as vehicle make (mass and volume). Cameras, perhaps the existing CCTV network, installed at entrance routes to the city capture the vehicles and send the images to a cloud computing platform that carries out number plate recognition as well as implements an algorithm to determine the presence. Using the registration and driver data base it is possible to obtain the make and consequently the vehicle specification such as mass and extent. Once the vehicle levy has been calculated for the day, an invoice can be issued to the owner of the vehicle, perhaps on a monthly basis. The time resolution could be an hour to start with with scope to refine to a minute in the future.
Example cars and proposed levy
Using UltimateSpecs I have compiled a table with the evaluation of the above formula for some commonly found cars, from very small ones to large SUVs. I have used a “gain” of £2 in the formula as well as the price for an entire day of presence, 8 hours, 3 hours and 1 hour.
The result is that small cars would cost a fraction of £1 for a full day in the city (green), between £1–5 for compact cars (white), £5–10 for larger saloons (light yellow), £10-£20 for medium sized SUVs (yellow) and £20 and above for large SUVs (orange). For instance, driving a child to school every day using a large SUV would cost in the order of £600 per annum (two round trips per day, say about 3h in total). Given this levy one would hope that cars in the city, in particular large SUVs, will become fewer and smaller again as well as used in a shared manner, or mobility would transform to using public transport services such as:
