Influence of Multiple Freeway Design Features on Freight Traffic Safety

Table 5

Safety effects estimation functions for large truck-involved crashes.

Freeway design elements	NB		MARS
	Functions	Interaction term	Functions	Interaction term
Inside rumble strips (IRS)		N/A	}	IRS  Curve
Outside rumble strips (ORS)		N/A		ORS  OSW
Inside shoulder width (ISW)		N/A		ISW  AADT, ISW  OSW, ISW  Curve
Outside shoulder width (OSW)		N/A		OSW  ORS
Number of lanes (NL)		NL  AADT		NL  AADT
Lane width (LW)		LW  Curve		LW  Curve

N/A: not available.