
Traffic data
Riseley has three Speed Indicator Devices (SIDs), one at each end of the High Street and one near Paulson’s Close.
The main purpose of a SID is to use its radar to measure, display and “influence” the speed of vehicles. They do this by showing the speed of the approaching vehicle in red, if it is above 30mph, with the comment “TOO FAST” and in green if it is travelling at 30mph or below with the comment “THANK YOU”.
To influence the speed and the behaviour of the driver, the Speed Indicator Device needs a long radar distance range of 100-200m, to give the driver time to see their speed, react and slow down if required. The radar must be able to look straight ahead and show several speed values to the driver, this allows enough time for the driver to slow down and for the display to give the driver positive feedback, a green “THANK YOU”, if they reduce their speed to 30mph or below.
Riseley Parish Council continues to monitor the effectiveness of our three SIDs.
Each is set to display information to oncoming traffic to help educate and inform drivers. SIDs are probably more useful as education devices than as speed recording devices.
- 0 to 30mph speed and ‘THANK YOU’
- 30 to 45 mph speed and ‘SLOW DOWN’
- 45 mph and above no speed but ‘TOO FAST’
Each SID records data in both directions, ie speed as cars approach the display and speed data as cars depart from the SID, where the display is not visable.
The SID records data regarding traffic volumes and vehicle speeds by the hour, day, week, etc, and we are able to analyse the data in detail. month to month. The traffic volumes will be less in the school holidays.
Nationally ROSPA show that 20% of all traffic exceed the 30mph limit by 5mph or more.
The 85th Percentile Speed is important, as it is the speed at or below which 85% of vehicles travel. It is used in setting speed limits and in determining whether the existing speed limit is appropriate. If, under free-flow conditions, 85% of traffic consistently travels at a significantly higher speed than the existing speed limit, then there may be a problem with the road layout. The Riseley data shows that cars increase their speed as they exit the village towards Swineshead and to a lesser extent towards Bletsoe.
There will unfortunately always be the odd vehicle recorded travelling at high speed, irrespective of the speed limit. The SID does not identify whether these are emergency vehicles or reckless drivers. Thankfully detailed analysis of the SID data shows that these are relatively isolated occurrences, and that the vast majority of vehicles travel within or close to the speed limits.
Riseley Summary SID traffic data July, June and August 2023
Location | Display visable | Average speed (mph) | 85th Percentile speed (mph) | ||||
---|---|---|---|---|---|---|---|
Jun | Jul | Aug | Jun | Jul | Aug | ||
Swineshead towards School | Yes | 27 | 27 | 27 | 33 | 32 | 32 |
School towards Swineshead | No | 31 | 31 | 31 | 38 | 38 | 38 |
School towards the Shop | Yes | 21 | 21 | 21 | 27 | 27 | 27 |
Shop towards School | No | 20 | 20 | 20 | 26 | 26 | 26 |
Bletsoe end of High St towards shop | Yes | 26 | 26 | 25 | 29 | 29 | 30 |
Bletsoe end of High St towards Bedford | No | 29 | 29 | 28 | 34 | 35 | 34 |
You can see the average speeds and the 85th percentile speeds are close to or under 30mph with the exception of vehicles exiting the village at either end of the High Street where the speeds are higher. In both cases the display is not visible and we suspect this plus the “open road” ahead, influences drivers to put their “foot down”. The proposed buffer 40mph zones at each end of the village might help.
Riseley SID Analysis
July 2023
Primary School From Swineshead - Display Visible
July 2023
Average speed | 27mph |
Vehicles exceeding 30mph | 24% |
85th Percentile speed | 32mph |
Average vehicles per day | 311 |

Primary School Towards Swineshead - Display Not Visible
July 2023
Average speed | 31mph |
Vehicles exceeding 30mph | 59% |
85th Percentile speed | 38mph |
Average vehicles per day | 471 |

Shop Towards Bedford - Display Visible
July 2023
Average speed | 21mph |
Vehicles exceeding 30mph | 3% |
85th Percentile speed | 27mph |
Average vehicles per day | 223 |

Shop Towards school - Display Not Visible
July 2023
Average speed | 20mph |
Vehicles exceeding 30mph | 3% |
85th Percentile speed | 26mph |
Average vehicles per day | 314 |

Bedford end of High Street From Bletsoe - Display Visible
July 2023
Average speed | 26mph |
Vehicles exceeding 30mph | 11% |
85th Percentile speed | 29mph |
Average vehicles per day | 454 |

Bedford end of High Street Towards Bedford - Display Not Visible
July 2023
Average speed | 29mph |
Vehicles exceeding 30mph | 39% |
85th Percentile speed | 35mph |
Average vehicles per day | 375 |
