A system broken into 2 different cycle lengths

[rmyers]

Is it possible to use TSPPD to have a corridor with 2 different cycle lengths? I need to have 2 different cycle lengths because of different traffic demands on each end of the system. Thanks

[bullock]

Yes, this is possible, especially if the two cycles are closely related harmonically (1x, 2x, 1/2x, 3x, 1/3x, 2/3x, or 3/2x).

Choose one of the cycle lengths to be the network-wide cycle length (specified in the View: Network Parameters), and then for each intersection running at the other cycle length, set the "adjusted cycle length" (specified in View: Intersection Parameters: Name, etc) to override the network-wide cycle length with the local cycle length.

If the two cycles are not closely related harmonically, then you're probably not too concerned with signal coordination between the two sections. There still may be benefit to keeping both sections in the same .Dgm file, so you can conduct travel time and delay studies (with the GPS receiver) along the entire corridor. Otherwise, you may prefer to split the corridor into two separate files. If you keep them in the same file, then for each intersection running at the other cycle length, I'd set the local adjusted cycle length to be as close as possible to the actual cycle length. Then I'd either accept the fact that the splits aren't exactly what's out in the field, or I'd set the splits (in seconds) to reflect what's in the controllers and live with the warnings from TS/PP-Draft about the splits not adding up to the cycle length. Either way, be warned, however, that the time-space diagram is showing a pseudo coordination between two sections running at non-commensurate cycle lengths, and that whatever coordination is apparent in the diagram will be achieved only occasionally (depending on the lowest common multiple of the cycle lengths).

Regards.
Greg