A Real-Time Location-Based Services System Using WiFi Fingerprinting Algorithm for Safety Risk Assessment of Workers in Tunnels

Table 2

Risk assessment and regulation.

Score	Action
>320	Dangerous, all on-site operations need to be stopped
160–320	Very dangerous, need change immediately
70–160	Dangerous, need change
20–70	Possible dangerous, pay attention
<20	A bit dangerous, it is acceptable