Toward harmonizing prospective effectiveness assessment for road safety: Comparing tools in standard test case simulations

Figures & data

Figure 1. Simplified flow diagram of the investigated safety system.

Table 1. Percentage of test cases where all participants had same results (either true for all events cyclist detected, algorithm fired, and collision avoided).

Sensor setup	Detected (%)	Fired (%)	Avoided (%)
Sensor small FoV	44	44	38
Sensor medium FoV	65	65	29
Sensor large FoV	85	85	47

Table 2. Minimal, maximal, mean, median and range values of detection rate, firing rate, avoidance rate and average speed reduction for all sensor setups and participants.

Statistical value	Detection rate (%)	Firing rate (%)	Avoidance rate (%)	Average speed reduction (km/h)
Min	65	65	27	13.5
Max	100	100	64	22.7
Range	35	35	36	9.1
Mean	82	79	47	16.4
Median	78	77	48	14.9

Table 3. Minimal, maximal, and range (maximum-minimum) values of the results of the flow of actions–based analysis. “Firing” relates to the moment where TTC falls below the threshold.

Action step	Test case	Type of result	Min	Max	Range
Decelerate VuT	Brake test	Time to stop (s)	2.222	2.288	0.066
	CVNB60small	Speed reduction duration (s)	1.126	1.165	0.039
	CVFB50medium	Speed reduction duration (s)	1.208	1.247	0.039
Activate brakes	Both cases	Brake delay (s)	0.2	0.246	0.046
Initiate braking	CVNB60small	Offset theoretical–actual firing (s)	−0.013	+0.031	0.044
	CVFB50medium	Offset theoretical–actual firing (s)	−0.061	+0.02	0.081
Calculate distance, speed	CVNB60small	Distance at firing (m)	16.431	17.209	0.788
		v{VuT} at firing (m/s)	16.666	16.674	0.008
		v{cyclist} at firing (m/s)	4.165	4.167	0.002
	CVFB50medium	Distance at firing (m)	13.889	15.677	1.788
		v{VuT} at firing (m/s)	13.88	13.889	0.009
		v{cyclist} at firing (m/s)	5.555	5.556	0.001

Figure 2. Variable definitions used for different TTC calculation methods. The left side shows a collision configuration with the hit-point in the middle of the car. The right side shows a collision configuration with a lateral offset between hit-point and middle of the car, where (Eq. 8) underestimates the TTC.