Topic: Cyclist Detection Loops

Hi All,
We've been hearing that some of us are having issues with the cycle detection loops shown in the P43 Signals Specification.

Can you please respond here with details of your issues, and also any details you have of how you fixed it? Maybe a different loop design, or different Q values?

Please post back here so we can update the P43 spec and keep it current.

Sean Lewis
Green Signal Consulting
sean.lewis@greensignal.co.nz
SNUG Committee Previous Chair

Re: Cyclist Detection Loops

Hi Sean
I carried out a number of investigations of cycle detection loops last year due to issues we were having with achieving adequate detection. I can't comment on the P43 specifications as we were directed not to use this layout on new installations in Christchurch. The reason being that this was tried in the past but was unsuccessful (possibly due to incorrect installation but I can't confirm). We had been using figure 8 loops but have found these to be unsatisfactory as they do not give a wide detection zone. Given the new standards for major cycleways many of the cycle lanes are wider and this creates large dead zones when using a figure 8. We have resolved this by using a simple rectangle loop which we have found works much better and is also easier to install. I believe both figure 8's and rectangles are useful depending on the situation. I can send you some further information on this if you're interested. I think the P43 layout has the potential to provide better coverage of the detection zone but this comes at a reduction in sensitivity which may be an issue for newer bikes with less steel. Ideally I would like to have carried out controlled testing of the P43 layout but have not had the opportunity. Would also like to see some of the new radar technology tested which has been used overseas and may work better than the loops. Would be good if NZTA, SNUG or one of the local authorities could take some leadership on this?
Cheers,
Mitchell