Reducing the utility from car use and ownership motivates substitution towards other forms of transportation, which benefits both the environment and public health. One way to cut the convenience of driving is enforcing parking regulations, because drivers have to park further from their destination when the option of illegal parking becomes less attractive. Parking at a greater distance also makes people walk more – a minor health benefit.
Enforcing speed limits and other traffic rules that slow cars down increases the time cost of driving. This may reduce wear and tear on vehicles and roads, which benefits the environment.
An implication of is that people who want to reduce global warming or improve public health should become volunteer parking wardens and traffic police by reporting parking violations, speeding and dangerous driving (preferably with photo or video evidence from phones or dashboard cameras).
A possible countervailing effect of the enforcement of parking rules occurs if the illegally parked cars obstruct the movement of other cars enough to motivate some people to switch away from driving. Then stopping the parking violations may open the road up enough to encourage more use of cars, with an overall negative environmental and health effect. Similarly, if reckless drivers make the roads unsafe enough to reduce others’ car use, then making traffic civil again may attract risk-averse people back to driving. However, in most developed countries, illegal parking and the ignoring of rules of the road is not severe enough to deter driving significantly, so better enforcement is likely to reduce car use.
Slowing traffic down may increase congestion and emissions per kilometre travelled if there is little substitution away from driving. Again, in developed countries public transit and cycling are usually feasible options. Of course, some people always find excuses not to use these, and in remote rural areas public transit may indeed be economically unreasonable and distances may really be too great for bikes. Electric bikes are then an option. These increase the range of travel with less pollution and congestion than cars.