1. Copyright © Siemens plc 2009. All rights reserved. Above ground SCOOT and MOVA detection in practice

2. Page 2 September-09 Siemens Mobility / Traffic Solutions Backgound SCOOT and MOVA are the strategies of choice for many Traffic Managers Both require accurate data about traffic conditions Traditionally this is supplied by loops Loops have many advantages, but also some disadvantages Obvious solution is to use above ground solutions! Advantages of loops Accurate Precise detection zone and position Immune to weather and lighting conditions Almost invisible when installed Cant easily be stolen Disadvantages of loops Difficult to install Vulnerable to damage Movement of the road surface Destruction when services are accessed Difficult to repair

3. Page 3 September-09 Siemens Mobility / Traffic Solutions Possible above ground technologies Several alternatives sensor technologies assessed by Siemens Corporate Technology (CT) Some found more suitable than others 77GHz radar seemed the best option Advantages Passive so can be very low power Accurate zones if multiple sensors used Immune to changing light levels Relatively low cost No significant maintence required Disadvantages Not good for detecting slow / static traffic Can be affected by environment (rain / snow etc) Passive Acoustic Technology Immune to light levels Relatively low cost No significant maintenance required Difficult to achieve precise detection zone Heavy rain / wind and snow can severally affect performance Active Acoustic Immune to changing light levels Very accurate zones possible No significant maintenance required Active device so needs radio approval in all target markets 77GHz Radar Passive so can be very low power Reasonably accurate zones possible Relatively low cost No significant maintenance required Can be affected by significant sudden temperature shifts Fog and heavy snow can affect performance Passive Infrared Many accurate zones possible (if field of view permits) Can provide visual overview of target area Can be badly affected by changing light levels and environmental conditions (Rain, snow etc). Significant maintenance overhead Video

4. Page 4 September-09 Siemens Mobility / Traffic Solutions Benefits of 77GHz radar Excellent target resolution Able to deliver very precise detection zones Important if SCOOT and MOVA loops are to be emulated accurately. Good immunity to adverse weather Small antenna size Minimal visual impact on-street Widespread acceptance of the frequency band Detector could be used worldwide with few limitations

5. Page 5 September-09 Siemens Mobility / Traffic Solutions Benefits of 77GHz radar But there was a big problem Cost!!! Detailed evaluation showed although it offered a very good technical solution, solid state 77GHz technology was in its infancy and the product costs were found to be very high. However, radar operating at 24GHz seemed to offer similar benefits at a much lower cost

6. Page 6 September-09 Siemens Mobility / Traffic Solutions Development challenges Product cost is a very significant driver when choosing technology solutions If these are too high product adoption in the market will tend to be limited, even if the performance achieved is good One interesting solution relates to the cost optimisation of the radar antenna and related circuits

7. Page 7 September-09 Siemens Mobility / Traffic Solutions Experiences in practice First tests based on ground truth principals at Poole test site Loop comparison Various traffic and weather conditions Initially only count and occupancy gathered in 5 minute bins Results looked very good

8. Page 8 September-09 Siemens Mobility / Traffic Solutions Experiences in practice Reference loop v Heimdall

9. Page 9 September-09 Siemens Mobility / Traffic Solutions Experiences in practice First tests based on a ground truth approach at Poole test site Loop comparison Various traffic and weather conditions Initially only count and occupancy gathered in 5 minute bins Results looked good But its is easy to be fooled by simple graphs! Focusing on the variation between the loop and Heimdall seemed to showed a different picture

10. Page 10 September-09 Siemens Mobility / Traffic Solutions Experiences in practice Difference between loop v Heimdall (Extract)

11. Page 11 September-09 Siemens Mobility / Traffic Solutions Experiences in practice Biggest variation occurred at night few vehicle in the sample set loop was found to be missing some fast moving motor cycles which Heimdall detected. Also the loop detected a number of vehicles driving close to the loop but in the opposite direction, Its easy to adjust Heimdall to avoid these vehicles Overall conclusion was that Heimdall count and occupancy performance looks good

12. Page 12 September-09 Siemens Mobility / Traffic Solutions Implications SCOOT SCOOT uses a measure of linear discounted occupancy to model queue build-up and dispersal (Link Profile Units - LPUs) The way a detector responds can significantly affect the LPU values that SCOOT calculates Typical detector sample Detector with poor turn-on response Detector with poor hold characteristics Count value accurate LPU value significantly lower Count value high LPU value only slightly lower (but likely not be consistent)

13. Page 13 September-09 Siemens Mobility / Traffic Solutions Implications SCOOT – LPU on test site Initial Heimdall LPU performance was disappointing! Further refinement of the detection algorithm proved necessary Performance much improved as a result. Still produces a slight lower LPU value than the loop Heimdall detection zone about 10% smaller than the loop Would be accounted for during normal validation of the link LPU:- Loop v Heimdall

14. Page 14 September-09 Siemens Mobility / Traffic Solutions Heimdall extended trials Several further Heimdall trial installations have been undertaken Different arrangements have been tested, Live installations With and without reference loops A full set of detailed results on all the trials will be available from the Siemens website Poole – Fleetsbridge Roundabout (SCOOT – count site) Southampton – Bittern Triangle (SCOOT) Bournemouth – Cemetery Junction (SCOOT – count site) Cardiff - Leckwith Giratory (SCOOT) Winchester. Battery Hill (SCOOT) Wimborne - Willett Arms (MOVA) Heimdall trial sites

15. Page 15 September-09 Siemens Mobility / Traffic Solutions Winchester – Battery Hill A single SCOOT detector has been installed in Winchester, along side a reference loop used by TRL. Data still being gathered from the Hampshire UTC system. Count correlation between loop and Heimdall were very good. LPU results re-confirmed that the Heimdall detection zone is a little smaller than a standard loop, but acceptable A view confirmed by a TRL assessment of the data from this site Poole – Fleetsbridge Roundabout (SCOOT – count site) Southampton – Bittern Triangle (SCOOT) Bournemouth – Cemetery Junction (SCOOT – count site) Cardiff - Leckwith Giratory (SCOOT) Winchester. Battery Hill (SCOOT) Wimborne - Willett Arms (MOVA) Heimdall trial sites Romsey Road Battery Hill

16. Page 16 September-09 Siemens Mobility / Traffic Solutions Summary The Heimdall detector provides good correlation to a loop Count accuracy is excellent SCOOT LPU values are a little lower than a standard loop but this can be addressed during validation MOVA performance has also been shown to be acceptable A full report on the Heimdall trials will be available from the Siemens website

17. Copyright © Siemens plc 2009. All rights reserved. Above ground SCOOT and MOVA detection in practice

18. Page 18 September-09 Siemens Mobility / Traffic Solutions Possible above ground technologies Advantages Passive so can be very low power Accurate zones if multiple sensors used Immune to changing light levels Relatively low cost No significant maintence required Disadvantages Not good for detecting slow / static traffic Can be affected by environment (rain / snow etc) Passive Acoustic Technology Immune to light levels Relatively low cost No significant maintenance required Difficult to achieve precise detection zone Heavy rain / wind and snow can severally affect performance Active Acoustic Immune to changing light levels Very accurate zones possible No significant maintenance required Active device so needs radio approval in all target markets 77GHz Radar Passive so can be very low power Reasonably accurate zones possible Relatively low cost No significant maintenance required Can be affected by significant sudden temperature shifts Fog and heavy snow can affect performance Passive Infrared Many accurate zones possible (if FOV permits) Can provide visual overview of target area Can be badly affected by changing light levels and environmental conditions (Rain, snow etc). Significant maintenance overhead Video

19. Page 19 September-09 Siemens Mobility / Traffic Solutions Winchester – Latest LPU results Battery Road – LPU (Reference loop v Heimdall) LPU 50 100 150 200 250 300 350 400 450 Loop Heimdall