A Hybrid Model for Prediction in Asphalt Pavement Performance Based on Support Vector Machine and Grey Relation Analysis

Table 4

Comparison of predicted and actual values of RDI.

Time	Original value	GRA-SVR		GM (1, 1)		GA-BP		PPI
		Predictive value	Absolute error	Predictive value	Absolute error	Predictive value	Absolute error	Predictive value	Absolute error
2011	94.0	94.00	—	94.00	—	94.00	—	94.00	−0
2012	90.2	90.27	−0.070	91.65	1.447	90.19	0	93.97	3.801
2013	90.1	90.03	0.068	90.47	0.368	90.10	−0.002	93.57	3.87
2014	91.4	90.63	0.724	89.30	−2.096	91.41	0.003	92.15	2.166
2015	89.8	89.73	0.070	88.16	−1.645	89.80	0	89.49	2.348
2016	86.4	86.47	−0.070	87.02	0.621	86.05	−0.352	85.84	3.091
2017	84.6	84.67	−0.066	85.90	1.301	84.26	−0.341	81.59	1.242
2018	85.5	85.56	−0.069	84.80	−0.704	86.58	1.082	79.10	3.907