Proposing New Methods to Estimate the Safety Level in Different Parts of Freeway Interchanges

Table 2

Characteristics of the interchanges investigated in the field studies.

Weaving area
Location	LW (m)	NW (−)	NR-ON (−)	NR-OFF (−)	VFW (veh/h)	VR-ON (veh/h)	SFW (km/h)	SR-ON (km/h)	SR-OFF (km/h)	Number of samples
Hemmat W-E: Yadegar ON and Yadegar OFF	304.71	5	2	2	6650	1264	90	40	40	13
Hemmat Freeway W-E: Asharfi ON and Yadegar OFF	705	5	2	2	6850	839	90	40	40	17
Hakim Freeway E-W: Sheikh Bahaee ON and Chamran OFF	296	4	2	2	2990	895	80	40	60	18
Karbala Freeway E-W: Sahne ON and Hamedan OFF	285	4	2	2	1870	185	110	50	60	21
Imam Ali Freeway S-N: N-N U-turn ON and Sabalan OFF	535.04	5	1	2	5860	157	80	40	60	19
Imam Ali Freeway S-N: Khavaran ON and Khavaran OFF	256	4	2	2	878	833	80	30	40	17
Merge area
Location	LACC (m)	VFW (veh/h)	NFW (−)	VR-ON (veh/h)	NR-ON (−)	SFW (km/h)	SR-ON (km/h)			Number of samples
Hemmat Freeway W-E: merge Asharfi N	145	5023	4	1253	2	90	50			11
Niayesh Freeway E-W: merge Chamran S	118	3794	3	909	2	80	40			14
Tehran-Qom Freeway N-S: merge Vahnabad E	173	2252	3	169	1	120	60			25
Tehran-Qom Freeway S-N: merge Vahnabad W	154	1266	3	440	1	120	60			19
Tehran-Saveh Freeway W-E: merge Shahriar W	225	2667	3	361	2	120	40			18
Diverge area
Location	LDEC (m)	NFW (−)	NR-OFF (−)	VFW (veh/h)	SFW (km/h)	SR-OFF (km/h)				Number of samples
Hakim Freeway W-E: diverge Sheikh Bahaee S	172	4	1	3188	80	30				17
Hemmat Freeway W-E: diverge Yadegar S	202	4	2	4196	80	60				13
Tehran-Saveh Freeway E-W: diverge Dehshade W	215	3	2	4160	120	60				22
Tehran-Saveh Freeway E-W: diverge Robat Karim E	180	3	2	1895	120	40				14
Yadegar Freeway N-S: diverge Kouhestan E	152	3	1	1930	80	50				9
Interchange ramps
Location	LR (m)	NR (#)	SLONG (%)	VR (veh/h)	RR (m)					Number of samples
Chamran S to Hemmat W	438	2	+3.8	1644	60					26
Hemmat W to Chamran S	350	2	+2.3	943	35					21
Imam Ali N to Mahallati W	402	2	+4.2	796	60					16
Mahallati E to Imam Ali N	514	2	+0.5	234	60					11
Niayesh E to Chamran S	470	2	−1.9	681	60					19