The Great IPC Speed Contradiction - Ickleford Parish Council publish much higher speeds for Road Hump consultation
IPC conducted a survey of the whole village in 2008 to determine how many supported the traffic calming measures proposed by Hertfordshire Highways. The consultation document can be seen at www.icklefordpc.com/Ickleford_Traffic_consultation_October2008.pdf.
After the scheme had been in place for a year the IPC sent a ‘Before & After’ review of the change in traffic speeds (see www.mostsimply.com/IPC_Before_and_After.pdf).
These 2 documents contradict each other.
The average speeds used to justify asking you to vote for traffic calming in the IPC 2008 consultation are considerably higher than the BEFORE average speeds later quoted by IPC in their ‘Before & After’ document. The 2008 consultation document gives residents the impression that traffic speeds were higher than the raw data from Hertfordshire Highways suggests it actually was.
Both documents say they are using the results of a traffic survey conducted by Hertfordshire Highways in 2007 (see Ickleford Speed Analysis for links to all the raw data supplied by HH).
We have asked IPC to explain why the 2008 Consultation document figures used to justify the need for traffic calming measures are considerably higher than the actual figures presented in their ‘Before & After’ review document. At the time of writing no response has been received.
Below is a road by road analysis of the figures published by IPC at each stage of the process highlighting the contradication.
Arlesey Road
In the IPC consultation residents are told that the “24 hour vehicle average speed” is 32.8mph (north) and 32.1mph (south):
We are not experts but have gone through all the raw survey data thoroughly and had our results checked by a mathematician and believe these figures should have been quoted as:
Near the school
24 hour vehicle average speed - 27.4 mph (north) & 26.8 mph (south)
07.00 - 1900 vehicle average speed - 27.0 mph (north) & 26.3 mph (south)
Near the Cricketers
24 hour vehicle average speed - 31.7 mph (north) & 30.0 mph (south)
07.00 - 1900 vehicle average speed - 31.3 mph (north) & 29.6 mph (south)
The IPC review document supports our figures and contradicts its own figures by telling residents the BEFORE “Average speed” near the school is just 27.1mph, and just 30.9mph near the Cricketers.
You will see that the IPC 24 Hour figures (32.8mph & 32.1mph) are more than 5mph higher (27.4mph & 26.8mph) than our average speeds outside the school. Also the IPC 7am to 7pm figures (36.1mph & 34.2mph) are more than 8mph higher (27.0mph & 26.3mph) than our average speeds outside the school.
Turnpike Lane
In the IPC consultation residents are told that the “24 hour vehicle average speed” is 32.2mph (north east) and 33.6mph (south west):
We are not experts but have gone through all the raw survey data thoroughly and had our results checked by a mathematician and believe these figures should have been quoted as:
24 hour vehicle average speed - 30.4 mph (north east) & 32.2 mph (south west)
07.00 - 1900 vehicle average speed - 30.0 mph (north east) & 31.7 mph (south west)
The IPC review document supports our figures and contradicts its own figures by telling residents the BEFORE “Average speed” is 31.3mph.
The IPC 7am to 7pm figures (35.3 & 37.2mph) are more than 5mph higher (30.0mph & 31.7mph) than our figures for the same period.
Bedford Road
In the IPC consultation residents are told that the “24 hour vehicle average speed” is 41.2mph (north) and 37.5mph (south):
We are not experts but have gone through all the raw survey data thoroughly and had our results checked by a mathematician and believe these figures should have been quoted as:
24 hour vehicle average speed - 36.5 mph (north) & 31.0 mph (south)
07.00 - 1900 vehicle average speed - 35.9 mph (north) & 30.0 mph (south)
The IPC review document supports our figures and contradicts its own figures by telling residents the BEFORE “Average speed” is 33.7mph.
You will see that the IPC 24 Hour figures (41.2mph & 37.5mph) are around 5mph higher (36.5mph & 31.0mph) than our average speeds. Also the IPC 7am to 7pm figures (41.9mph & 37.1mph) are more than 6mph higher (35.9mph & 30.0mph) than our figures for the same period.