Quoted from Greenham Common

At 12:45 there was ~450 spaces in Northbrook St/Parkway.  Why the heck are those two carparks aggregated when they are roughly 0.6 miles drive a part?

The signs chosen have three displays - there are six car parks monitored.  The three on  the wharf are aggregated (makes sense to me).  So coming from the south you see the KC Park, Wharf and the two north of the river as the three numbers. Can't see how they could do it otherwise once they have a 3 number display.

Perhaps they should have chosen 4 number displays, perhaps there is some research that says the fewer numbers they show the more likely a driver is to take in the infomation?

Actually it makes sense.  As you make the journey, you can make your choice to proceed or not.  The journey to N'brook St and PW is the same, until you see the sign just after the roundabout where it tells you the spaces for each.