Patent ID: 11941978
Assignee: TRAFFIC TECHNOLOGY SERVICES, INC.
Field: Control (Instruments)
Classification: CPC G | IPC G

Claim 9:
10. A method comprising:
selecting a subject intersection, wherein the subject intersection is a physical intersection controlled by electric traffic signals based on at least one timing plan;
accessing a first datastore to acquire MAP data that defines detailed geometries of the subject intersection, including stoplines, movements and lane alignment data;
defining a geo-fence area around the subject intersection based at least in part on the MAP data;
accessing a second datastore to acquire a set of trajectory data that were received from a plurality of wirelessly-connected vehicles over an analysis period of time, each instance of the trajectory data including one or more of a date/time stamp, GPS location, and speed vector of the corresponding vehicle;
applying clock drift adjustments to the date/time stamps of the trajectory data to form a corrected trajectory dataset wherein the data is temporally aligned to actual state changes of the traffic signals at the subject intersection;
filtering the corrected trajectory dataset to select data in which an indicated GPS location is inside the geo-fence area to form a local dataset;
process the local dataset to group trajectory points based on a journey id in each datum for at least some of the vehicles in the local data set, each group of trajectory points representing the corresponding vehicle's trip through the subject intersection;
identifying a set of observed movements based on which vehicles move together according to the local dataset;
overlaying the observed movements on the subject intersection MAP data to identify stopline crossing datapoints (“crossings”) for each journey, each stopline crossing datapoint including its corresponding clock drift-adjusted timestamp;
applying statistical analysis to the adjusted timestamps of the crossings to identify signal phases;
determining a timing cycle length that best causes the crossings from each approach to occur during the same portion of the cycle over the timing plan's coverage time period;
determining barriers from the crossings as the points in the cycle that separate crossings from conflicting approaches;
adjusting cycle offset so one phase does not wrap-around in ring barrier diagram;
determining a start of green time for each approach's movements based on when the earliest point in the cycle that crossings are typically observed for that movement restricted to the barrier for that approach; and
generating, based at least in part on the identified signal phases, the timing cycle length, the barrier, and the start of green times, a first timing plan for the subject intersection.