In the interest of safety of passengers, Indian Railways have to resort to the rescheduling/cancellation of trains due to foggy weather conditions in Northern Parts of the country.
Fog PASS Device is a Global Positioning System (GPS) based hand held portable device which serves as an aid for the crew during foggy weather through audio visual alarm, whenever any landmark comes within the Geo-fence range. Location of stations, warning boards, signals, level crossing gates and Whistle for Level crossing (W/L) boards in the section is fed in the equipment. It displays speed of the locomotive, distance and time to reach landmarks and is carried by the Loco Pilots. These are being used only in those zones of Indian Railways where the trains pass through fog affected region.
Details of Fog PASS Devices procured and provided to Zonal Railways, which are affected by foggy weather conditions, are as under:
| ZONAL RAILWAY | NUMBER OF DEVICES PROVIDED |
| EAST CENTRAL | 877 |
| NORTHERN | 2648 |
| NORTH CENTRAL | 537 |
| NORTH EASTERN | 975 |
| NORTHEAST FRONTIER | 1101 |
| NORTH WESTERN | 802 |
| TOTAL | 6940 |
6000 nos. more Fog PASS Devices have been sanctioned and included in Pink Book 2018-19. Purchase order for 6000 units has already been issued in August, 2018.