JOHNNY, "I thought they were not supposed to break one law to enforce another?"
It is not necessarily an offence for emergency services to exceed the speed limit.
Road Traffic Regulation Act 1984
Section 87(1)
"No statutory provision imposing a speed limit on motor vehicles shall apply to any vehicle on an occasion when it is being used for fire brigade, ambulance or police purposes or for or in connection with the exercise of any function of the Scottish Fire and Rescue Service, if the observance of that provision would be likely to hinder the use of the vehicle for the purpose for which it is being used on that occasion."