Design and Research of a Vehicle Approaching Reminder Device Based on ZigBee Wireless Sensor Network

Table 1

Data comparison of different initial speeds and adhesion coefficients on braking distance.

Initial speed of vehicle (km/h)	Driver reaction distance (m)	Dry asphalt pavement	Wet cement pavement	Wet asphalt pavement	Snow pavement	Icy road
		Adhesion coefficient 0.7	Adhesion coefficient 0.6	Adhesion coefficient 0.5	Adhesion coefficient 0.2	Adhesion coefficient 0.1
20	5.55	2.36	2.73	3.26	7.96	15.85
25	6.95	3.62	4.21	5.03	12.42	24.72
30	8.32	5.15	6.02	7.17	17.82	35.51
40	11.12	9.11	10.58	12.68	31.57	63.08
50	13.88	14.15	16.51	19.79	49.28	98.49
60	16.68	20.33	23.72	28.45	70.95	141.77
80	22.23	36.11	42.11	50.51	126.02	251.97