Table 3: Comparison of tunnel incident detection systems.
| Category |
VDS-Based Algorithmsa
|
Video Incident Detection Systemb
|
AADS (This Study) |
| Performance |
DR |
85-95% |
14-85% |
80-95% |
| FAR |
0.03-0.35% |
15-85% |
2.6-3.5% |
| MTTD |
156-306 s |
10-120 s |
1 s |
| Operations characteristics |
Calibration |
Difficult |
Difficult |
Easy |
| Installation height restraint |
No |
Yes |
No |
| Influence of occlusion |
No |
Yes |
No |
| Tunnel incident types |
Fire |
X |
O |
X |
| Crash |
X |
X |
O |
| Wrong-way maneuver |
X |
O |
X |
| Debris |
X |
O |
X |
| Stopped vehicle |
X |
O |
X |
| Queue |
X |
O |
X |
| Slow vehicle |
X |
O |
X |
| Skid |
X |
X |
O |
| Pedestrian |
X |
O |
X |
| Change in traffic flow |
|
X |
X |
Note: DR = Detector Rate; FAR = False Alarm Rate; MTTD = Mean Time To Detection; O = Detection is possible; X = Detection is impossible.
aSource: Comparison and Analysis Tool for Automatic Incident Detection, Transportation Research Record, No. 1925, 2005.
bSource: Video Incident Detection Tests in Freeway Tunnels, Transportation Research Record, No. 1959, 2006.