How do users use TSPP Draft?

[mtaylor]

I am interested to know how other TSPP-Draft users use the optimization features of TSPP-Draft.

Do you use only TSPPD for development of cycle length, offsets and splits?

Do you use other software, such as Synchro to develop cycle length, offsets and splits and then use TSPP Draft to fine tune the splits and offsets?

Do you perform travel time runs using TSPPD on existing corridors and use the optimization features to fine-tune just splits & offsets?

Do you use TSPP Draft just for MOE's for travel time runs?

How do you use TSPP Draft?

[Donald Bennett]

We primarily use the program to evaluate T7F timing plans. I differ in philosophy on the bandwidth solution process that maximizes band regardless of position in the cycle. I like the vehicle that starts at the first critical intersection to progress as far as possible before stopping, then I try to maximize the bandwidth with that constrataint. I use T7F for the cycle, splits and prliminary offsets, code those into TSPPDraft, then use TSPPD to "fine tune" the offsets. We also use the program to do our floating car studies and fine tune offsets while riding the system.

[bullock]

Here's a "collective" response based on my memory of conversations with users over the years. All the same, additional posts by other users are most welcome.

For every example purpose you listed, I've talked with people who use the software exclusively for that purpose, with one modification. The modification is that we change "splits" to "phase sequences" -- users have talked about optimizing or fine-tuning the phase sequences, but I'm not sure I recall anyone mentioning that they use the software for optimizing or fine-tuning the splits. As you know, the software isn't capable of analyzing a single intersection and recommending its optimal cycle length and splits, so I think users have generally taken the splits from either the controllers or from suitable analysis software, then worked with those splits in TS/PP-Draft.

Other uses of TS/PP-Draft mentioned over the years include:

- Documenting a time-space or platoon-progression diagram for each artery and each timing plan. Some use time-space diagrams exclusively, and some use only platoon-progression diagrams (to see explicitly the delay and queue for the through traffic),
- Advising city planners and city councils about how proposed developments will affect traffic flow,
- Explaining to the public or to local politicians why certain timing decisions were made and why a suggested change to the coordination is advisable or inadvisable. A number of users have said that they take a laptop to public meetings to run the software in front of the public and city officials because laymen quickly understand how to read time-space diagrams and that it makes a persuasive demonstration of the effects of changes to the timings,
- Conducting a before-and-after travel time and delay study to document the emissions reductions from signal timing improvements and apply for federal funding to pay for the improvements, and
- Preparing speed-vs.-distance plots for freeway systems to locate persistent bottle-necks. It may surprise many of the long-time users to learn that there are cases where this is the only purpose for which the software is used.

Greg