Well, not everyone will buy/hire a driver -less car and smart parking technology is one of a number of options that will help reduce congestion and make life easier for motorists and residents.

And don't forget the more mundane but effective changes that can be implemented now at much lower cost and faster.

With geo-spacial tracking directing civil enforcement officers to the streets where vehicle congestion is highest so they are more effective. 

Analytics to show penalty charge notice status- how many issued, paid, open and cancelled so the "production line"can be managed effectively. How many not processed but getting near the 6 month time period in which they must be or the revenue is lost forever.

Online appeals process with photo and video data with fast response rather than having to be posted with consequent delays. 

Revenues from parking offenders can be re-invested in smart parking solutions but not if they are lost forever. Doing the simpler things first can get faster results as shown by  Islington Council    . 

That is not to say that smart parking apps are not important just that they will take their place in a wide range of "Smart City" "Smart Highway" "Smart parking" solutions which should complement each other