Parkeon, Verrus, Parkmobile, Cale, Duncan, and I believe IPS are currently involved in Parking Pilot Programs in the District of Columbia. Read all about it here
The city has carved out areas and each company has installed its equipment. The idea is that DC will be able to see just how each type of system works – Some are pay by cell, others pay and display, others pay by inputting license number. They are concerned about long range decisions and these test programs should give them good data when making such choices.
I guess that this is not a program to find out which is the preferable supplier, but which technology would be most acceptable to the populace.
My suggestion is that cities not tie themselves too closely to one solution, but they have the flexibility to offer many payment methods, types of solutions (Pay and display, in car meter, license number, single space meter, etc.)
If people have a myriad of solutions, you are offering choices. What is best for one driver (pay by cell for a techonut) may not be good for a company with a fleet of trucks (where debit card might be preferable.) Visitors who come once a year might like familiar meters or pay by cash, while those driving in town every day might love a pay by cell application. The more choices, the more convenient.
JVH