Adaptive Control Systems Survey

Adaptive Control Systems Survey University of Utah Traffic Lab Peter T. Martin Associate Professor University of Utah

Presentation Outline • Scope of Survey • The Questions • Summary of findings

Agency System Intersections 1 City of Anaheim, CA SCOOT 22 2 Orange County, FL SCOOT 13 3 City of Minneapolis, MN SCOOT 56 4 City of Toronto SCOOT 300 5 Oakland County, MI SCATS 575 6 Minnesota DOT SCATS 71 7 City of Tucson, AZ RHODES - 8 City of Tempe, AZ RHODES 1 9 New Jersey DOT OPAC 12 Agencies

System Age • 1990 to • 2003

General Observations • most agencies are satisfied with ATCSs • Because • they adapt to varying traffic conditions • such as daily traffic and special events • all agencies agree that successfully operating and maintaining the system is a substantial time investment • to gain proficiency, a person must spend at least one year with the system.

Questions • Set up – how did it go? • Level of Effort on setting up the System • Understanding the System • What does the system handle well? • What are the traffic operation features that the System does not handle well • Lessons learned

What was the level of effort, by installer, to make the System operational ? • 5 to 6 weeks To • 12 months

What was the level of effort by City staff to make the System operational? • One month to one year • “…Significant effort in the beginning…” • “…multiple agencies a problem…”

What was the level of effort to understand the System operation (on a day to day basis)?

How much time did it take? (SCOOT) • 2 City engineers working full-time side by side • + 2 experts for over two months immediately following installation of the system (SCOOT)

How much time did it take? (SCOOT) Training • Classroom (5%) introductory material, hands-on • data preparation (15%) • hands-on field timing development & fine- tuning (80%) • +2 weeks of personnel time on-site follow-up

How much time did it take? (SCATS) • “…SCATS is a high level signal system. The complexity is directly proportional to its ability to move traffic. As a result, the system takes many years to learn, and even more to become truly proficient…”

How much time did it take? (SCATS) • “…New Windows based software has made training easier, but the underlying philosophy and logic is still complex.

How much time did it take? (SCATS) • “…SCATS is very powerful and an excellent system, it just takes time to fully understand.

What are the traffic operation features that the System handles well ? (SCOOT) • Double cycling features • Can have significant on-street benefit particularly • off-peak • peak period shoulders • special events

What are the traffic operation features that the System handles well ? (SCOOT) • However, • “…the benefit can only be realized if the system is properly setup and maintained…”

What are the traffic operation features that the System handles well ? “… SCOOT has a green wave feature that would allow the signals to be set such that a platoon could advance along a corridor unimpeded or for use with emergency vehicles.

“… During President Bush’s visit to make a speech at the convention center last November, the entire corridor was closed for 30 minutes and traffic backed up for miles behind the barricades. When the street was open, both audience traffic exiting the convention center and traffic waiting behind the barricades cleared the area within 20 minutes.

What are the traffic operation features that the System handles well? • Emergency vehicles pre-emption (SCOOT) • Responds well to incidents or construction where the capacity of (SCOOT & SCATS)

“…During the PGA Merchandise Conference last January, 70,000 attendees were able to easily ingress and egress the convention center without manual traffic control by police. In previous years, more than $80,000 used to be spent on manual traffic control during each major event.

Level of Effort • System contractor • City or/and state staff • Anaheim, CA: SCOOT 22 intersections, 2 months • Minneapolis, MN: SCOOT 56 intersections, 18 months

How long to understand the System? • Basic understanding • General traffic engineer (4-6 months) • Experienced signal timing engineer (2 months) • Proficiency (1 year or more)

What are the traffic operation features that the System does not handle well • “… SCOOT user interface needs improvement. • “…Special detector placement is required for short links less than 100 meters, otherwise a minimum fixed green time must be provided for those links. (SCOOT)

What are the traffic operation features that the System does not handle well “…controller personalities is kind of a pain…” (SCOOT)

What are the traffic operation features that the System does not handle well • “…The Delta 3 controller interface is not user friendly. Technician are used to NEMA controllers. (SCATS) • “… x expressed that he did not have enough experience to know what the System does not handle well. (SCATS)

In hind-sight, what would you have done differently during the implementation of this System?i.e. Lessons Learned

Lessons Learned 1/10 • “… When the SCOOT system was installed there should have been more effort on the graphical user interface (GUI). • “… Prior to the validation process, construction inspectors should verify detector configuration. (SCOOT)

Lessons Learned 2/10 • Social economic evaluations show that the investment has been recovered in less than a year, which means that this is a project with high social revenue. (SCOOT & SCATS) • System operators should test communication equipment. (SCATS)

Lessons Learned 3/10 “…County staff should be trained to design and validate the system for future expansions or troubleshooting…(SCATS)

Lessons Learned 4/10 • “… the selection of and monitoring of the evaluation consultant could have been better… • “…Several mistakes were made by the consultant in gathering before-and-after data, rendering the project report relatively useless with regard to performance of the system…

Lessons Learned 5/10 “…Do not change your “normal” traffic engineering strategies or overall approach to signal timing just because you are going with adaptive control. For example, set maximum cycle times and phase durations that you are comfortable with…” (SCOOT)

Lessons Learned 6/10 “… Under a long run perspective and without budget constraint, we would have studied more in depth better ways to communicate between the traffic light and the control centers… (SCATS)

Lessons Learned 7/10 • dynamic control system, we have found from the last evaluations, that network configuration must be studied with more detail (SCOOT & SCATS) • the dynamic control loops must be built downstream from bus stops, and if necessary, they must be moved (SCOOT & SCATS)

Lessons Learned 8/10 • We should have gone with lamp monitoring. This was an extra device and relatively expensive but would have been very beneficial (SCOOT & SCATS) • Should have worked on smaller implementation chunks. Went from 15 intersections to 68 intersections in one jump. It is better to work incrementally (SCOOT & SCATS)

Lessons Learned 9/10 • Would have worked out hardware problems ahead of time. difficult it would be to get a 2070 controller working in a TS2 cabinet (SCOOT & SCATS) • utilize system hardware that has been proven in the field under the harsh environmental conditions that exist (SCOOT & SCATS)

Lessons Learned 10/10 • Fully bench test the system hardware and software before implementation in the field (SCATS) • Set up a better maintenance program so that the system can be adequately maintained (SCOOT)

Conclusions • Agencies are very satisfied with their systems • ASC takes more time to implement than anticipated • ASC takes more time to learn than anticipated • Evaluations are important

Adaptive Control Systems Survey