Applying Clustered KNN Algorithm for Short-Term Travel Speed Prediction and Reduced Speed Detection on Urban Arterial Road Work Zones

Table 6

Impact analysis result of road work based on actual data.

Time		Predicted travel speed (km/h)	Average travel speed at normal conditions (km/h)	Standard deviation of travel speed at normal conditions (km/h)	z-score	Whether the construction affects the speed	Speed degradation (%)
t + 1	10:30	19.36	21.29	1.51	1.28	No	—
t + 2	10:35	19.48	21.65	1.50	1.45	No	—
t + 3	10:40	19.52	21.65	1.45	1.47	No	—
t + 4	10:45	19.48	21.77	0.92	2.49	No	—
t + 5	10:50	19.44	21.97	1.35	1.87	Yes	−11
t + 6	10:55	19.28	21.58	1.12	2.06	No	—
t + 7	11:00	18.84	21.84	1.21	2.47	Yes	−11
t + 8	11:05	18.64	22.35	1.60	2.32	Yes	−14
t + 9	11:10	18.60	22.39	1.60	2.36	Yes	−17
t + 10	11:15	18.56	22.45	1.43	2.71	Yes	−17
t + 11	11:20	18.72	21.94	0.89	3.60	Yes	−15
t + 12	11:25	19.04	22.10	0.79	3.87	Yes	−14