Highway Traffic Speed Prediction in Rainy Environment Based on APSO-GRU

Table 4

The division of different periods of the day.

Period number	Time span	Characteristic
1	0:00–4:00	During the low period in the morning, the speed and flow decrease slowly
2	4:00–8:00	During the rising period, the speed and flow increase rapidly
3	8:00–12:00	In the morning peak, the speed and flow are high
4	12:00–16:00	In the afternoon, the peak was flat, and the speed and flow decreased smoothly and slowly
5	16:00–20:00	In the evening peak, the flow reaches the peak again, and the speed decreases gradually
6	20:00–24:00	In the low period of night, the speed and flow decrease rapidly