Urban Traffic Flow Forecast Based on FastGCRNN

Algorithm 1

Generate traffic flow time series for different roads.

(1)	Initialize: time_interval = 5 min (or 30 min), begin_time = 2015-01-01 00:00:00, roadflow[roadid][time_num] = 0
(2)	For Every data record do
(3)	time_num ←(time–begin_time)/time_interval
(4)	End for
(5)	All data records are grouped by car_id, sorted by time_num within the group
(6)	For each group records do
(7)	Remove duplicates records based on road_id and time_num
(8)	Count roadflow
(9)	End for
(10)	Output: roadflow