They were closer.... :D :D :D
A 999 call would have resulted in the operator contacting Witham police station to send a unit, Jeremy did not save time by searching for phone numbers in yellow pages, then after receiving no answer at Witham, speaking to Chelmsford, who put him on hold whilst speaking to HQ (also in Chelmsford where 999 calls are answered), then remaining on hold whilst Chelmsford contacted Witham.
A 999 call would have resulted in a quicker response, perhaps not by much, but even the time spent looking for numbers would have been saved (up to 10 minutes).
The slowing down for the police to pass doesn't bother me, unless he went at that speed for the entire journey.