Gap-accepteance parameters for roundabouts: a systematic review

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Table 8 Summary results for follow – up headways at double-lane roundabouts - right entry lane

study name	subgroup within study	mean [s]	sample size	st error [s]	Z - value	Q	I² [%]
Gazzarri et al. [45]	A₁	2.70	205	0.05	54.45	17.77	9.98
Gazzarri et al. [45]	A₂	2.44	29	0.11	22.65	17.77	9.98
Gazzarri et al. [45]	A₃	2.91	143	0.06	45.79	17.77	9.98
Gazzarri et al. [45]	A₄	2.58	87	0.07	39.45	17.77	9.98
Gazzarri et al. [45]	A₅	2.59	92	0.07	36.00	17.77	9.98
Rodegerdts et al. [61]	B₁	3.10	648	0.06	52.61	17.77	9.98
Rodegerdts et al. [61]	B₂	4.40	2	1.63	2.71	17.77	9.98
Rodegerdts et al. [61]	B₃	3.10	104	0.11	28.74	17.77	9.98
Rodegerdts et al. [61]	B4	2.80	478	0.04	76.52	17.77	9.98
Rodegerdts et al. [61]	B₅	3.10	1340	0.03	94.57	17.77	9.98
Rodegerdts et al. [61]	B₆	3.00	1773	0.03	114.84	17.77	9.98
Zheng et al. [17]	C₁	3.00	425	0.06	51.54	17.77	9.98
Zheng et al. [17]	C₂	2.80	2206	0.02	119.56	17.77	9.98
Zheng et al. [17]	C₃	2.20	22	0.11	20.64	17.77	9.98
Zheng et al. [17]	C₄	2.60	128	0.11	24.51	17.77	9.98
Zheng et al. [17]	C₅	2.20	600	0.03	67.36	17.77	9.98
Zheng et al. [17]	C₆	2.02	17	0.12	18.14	17.77	9.98
summary effect (random)		2.72		0.08	35.74	17.77	9.98