1. Cycle Detection at Signalsthoughts for Consideration Jonathan Slason (Beca) and YuliaVugman (Auckland TMU) Presented: SNUG 15 November 2010. Wellington, NZ Thanks to the Auckland TMU for their technical input and photographs The views expressed are those of the author and do not necessarily reflect those of Beca or any other organisation or agency. Further detail behind the issues raised is available by contacting jonathan.slason@beca.com
2. Cyclist Detection discussion Discussion of Cycle Detection, primarily loops Can we develop a consistent approach Can we better plan for cyclists at our signals
3. Types of Detection Loops Cheap (initially) Familiar Easy to install in a vary of locations Video Line of sight and large vehicles blocking views Perceived cost Lack of trust, maintenance, hardware placement constraints Radar/Microwave Used anywhere?
4. State of the State in Auckland Region Increased use of the Advanced Stop Box (ASB) Auckland City (Transport?) aims to put them almost everywhere possible as the default option Increased cycling demand The latest manual data from March 2010 showed that Lake Road was the busiest of 13 cycle count sites in North Shore City with 327 cycle movements per day – a 12 percent increase compared to 2009. “The ARTA cycle counts in March 2010 showed a whopping 27% increase in cycling over the whole region, with Auckland City coming from behind to reach the highest gains at plus 40%! Rodney and Manukau also showed great increases at plus 39% and plus 36%.” Use of Bike/Bus lanes
5. High-Tech Cycling Counters The high-tech counters are located across the Auckland region at: - Lake Road, Takapuna, North Shore - Tamaki Drive, Auckland City - Orewa Walkway, Orewa - Twin Streams Walk/Cycleway, Henderson - Northwestern Cycleway, TeAtatu - Northwestern Cycleway, Kingsland - Great South Road/Cavendish Road , Manukau - Upper Harbour Bridge , Greenhithe, North Shore - Highbrook Cycleway, East Tamaki
6. Issues ASBs Majority don’t have loops Movements aren’t called without vehicle demand Locking calls simply aren’t sufficient on the symmetripoledesign Loop placement and accurate cycle detection Symmetripole/Rectangles may not be best for cycle detection Inductance highly variable depending on the exact placement of the cycle rim on the loop. Requires improved detection methods Number of Loops Constraints placed by SCATS
9. Issues A disadvantage of the conventional quadrupole loop design shown in Figure 7. above is that under marginal operating conditions (a low-conductance bicycle, a low-sensitivity setting, or a large loop footprint) it requires the bicycle wheels to be positioned in a precise location (over the center wire) for detection to occur reliably.
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11. Depending on the Loop Design the location of the cycle placement is critical to making a solid detection. Some cyclists may not be aware of the best part of the loop for detection, or may not be aware of the function of inductive sensors in the first place. If circular, or rectangular loops are used, location is critical and can be enhanced by markings and signage. The Quardupole design or Type D are used, this reduces the need for specific cycle rim placement. USA MUTCD Cycle Loop Marking
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13. We have not standardised and agreed on any particular shape or configuration of detector loops to be used to detect the bicycle. According to the NEW ZEALAND SUPPLEMENT TO AUSTROADS GUIDE TO TRAFFIC ENGINEERING PRACTICE PART 14 - BICYCLES September 2008: “Bicycle detector loops are commonly square, rectangular or elongated diamond. They vary in length and width, depending on the lane(s) and movement they are intended to cover. In New Zealand a "System D" loop is commonly known as "Slanted". They may also be referred to as "Chevron" loops or simply as XYZ loops (depending on their position or location).”
14. Operational & Policy Considerations In sites where bicycle loops are installed, we are still not taking advantage of features such as: Early starts for bike riders (also called late starts for vehicles, cyclist head starts, leading intervals) Early starts in conjunction with bus priority (in situations where buses and bike riders share the same lane and buses are given an early start, bike riders are also given an early start) Green bicycle lantern when pedestrians are called , etc. Options for Variable signal timing based on cycle detection (longer clearance intervals, etc.)
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16. CCC shifts the standard Symmetripole loop design into or immediately adjacent to the cycle lane to capture both cycle demands and vehicle demands.
