Freeway Traffic Speed Estimation of Mixed Traffic Using Data from Connected and Autonomous Vehicles with a Low Penetration Rate

Table 1

Existing studies on CAV simulation by the internal model.

Parameters	Default value	Atkins [29]	Aria et al. [30]	Tibljaš et al. [31]	Stanek et al. [32]	Sukennik [28]	Asadi et al. [33]
Version of VISSIM	VISSIM 9	VISSIM 8	DK	DK	VISSIM 9	VISSIM 11	VISSIM 10
CC0, standstill distance (m)	1.50	—	—	1.00	1.25	1.00	1.00–1.50
CC1, headway time (gap between vehicles) (s)	0.90	—	0.30	0.50	0.25	0.60	0.50–1.50
CC2, car-following distance/following variation (m)	4	0	—	1.00	3	0	0
CC3, threshold for entering following (s)	−8	—	—	—	−12	−6	−8
CC4, negative following threshold (m/s)	−0.35	0	−0.56	−0.10	—	−0.10	0
CC5, positive following threshold (m/s)	0.35	0	0.56	—	—	0.10	0
CC6, speed dependency of oscillation (1/(m/s))	11.44	0	—	0	0	0	0
CC7, oscillation during acceleration (m/s^2)	0.25	—	—	0.40	—	0.10	0.15–0.45
CC8, standstill acceleration (m/s^2)	3.50	—	—	4	—	4	3.30–3.90
CC9, acceleration at 80 km/h (m/s^2)	1.50	—	—	2	—	2	1.30–1.90
Look-ahead distance	0 to 250 m	—	150–200 m	0–105 m	0–500 m	0–250 m	0–800 m
Look-back distance	0 to 150 m	—	150–200 m	0–280 m	0–250 m	0–150 m	0–800 m
Observed vehicles	2	10	6–8	—	10	99	10
Smooth close-up behaviour	No	—	—	Yes	—	—	Yes
Accepted deceleration, trailing vehicle (m/s^2)	−1	—	—	—	—	−1.50	—
Minimum headway, front/rear (m)	0.50	—	—	—	0.40	0.50	0.20–0.70
Safety distance reduction factor	0.60	—	—	—	0.45	0.75	0.30–0.80
Maximum deceleration for cooperative braking (m/s^2)	−3	—	—	—	−4	−6	—
Cooperative lane change	No	—	—	—	Yes	Yes	Yes
Maximum speed difference (km/h)	3	—	3	—	—	10.80	10.80