Human perception of the information on the road signs is a critical factor in determining the safe use of both the vehicle and the interacting environment. A total of 30 road traffic signs which includes10-warning, 10-regulatory and 10-informatory signs were evaluated using 190 questionnaires to determine comprehension level of road users in Kano. The questionnaire was administered to both private and commercial drivers of trucks, cars, tricycle, motorcycle, and bicycle. Majority of the respondents are male (91.6%) which is due to the disproportionate ratio between male and female drivers in Kano city and 90% of them are youth below the age of 40 years showing that majority of the state drivers are young people. The comprehension level was found to be good 79%. The least comprehended signs in Kano are "park and ride" with comprehension level of 54.7%, followed by "Narrow bridge" (60%), "line merge ahead" (62.1%), "slippery road" (63.2%), "No entry for all vehicles" (70.5%). The signs with up to 90% recognition were "fuel station", "stop sign" and "school crossing". Sex, education, driving experience and type of vehicle used seems to affect the comprehension level of drivers in Kano. Truck drivers have a poor understanding of the traffic signs lower than all other classes of road users (65%).

The increase in number of vehicles and deterioration of the existing facilities necessitates the need to improve the existing roadways and to build additional highways hence creating more work zones in cities around the globe. Two work zones one on a rural road and one on an urban road were studied to identify potential hazards in work zone and determine the most dangerous area of the work zone using risk concentration level. Confusing signs, use of dangerous devices for road closure, missing buffer, missing tapers, use of non-retro reflective devices, unprotected work area, dangerous flagging, missing safety alarms for heavy machineries, speed, aggressive driving and improper pedestrian access are the most dangerous hazards in work zone having a very high risk level. Transition area was found to be the most dangerous area of the work zone with a very high risk concentration level followed by working area with high risk concentration level, then advance warning area with medium risk concentration and finally termination area also with medium risk concentration. Proper installation and maintenance of temporary traffic control devices, use of safety attires by workers, fitting all moving machineries with safety alarms, use of retro reflective devices, protecting work activities, providing buffers for workers, and law enforcement will improve safety of the work zones.