Predicting Real-Time Crash Risk for Urban Expressways in China

Table 1

The main factors influencing the crash risk under different data training conditions.

Data selection period (prior to crash occurrence)	The main factors influencing the crash risk
0 to 5 min	, , , ,
0 to 10 min	, , , ,
0 to 15 min	, , ,
0 to 20 min	, , , , , ,
0 to 25 min	, , , , ,
0 to 30 min	, , ,