1.2. Planning and Considerations

This is one of the most critical elements of good worksite traffic management. When proper thought is put into the layout and planning of any worksite the potential for an accident decreases. This is achieved because correct equipment, personnel and associated safety issues are taken into account prior to the work commencing. This leads to greater productivity and greater safety, as action on site is planned and issues have already been resolved. There is also increased awareness because works personnel are actively thinking about the worksite and methods to improve existing layouts. 

Planning considerations:

1.Management of vehicular and pedestrian traffic

When planning roadworks, consideration has to be given to the management of vehicular and pedestrian traffic.  This planning needs to consider the volumes as well as the speed of vehicles. 

Subject to the nature of works being undertaken, traffic can generally be managed in one of the following ways: 

• Through the work site
• Adjacent to the work site
• Via a detour or sidetrack (temporary road) around the work site. 

The main aim in planning is to minimize disruption to traffic as well as to the progress of the roadworks, while providing a safe environment for both.  The safest approach may be to move traffic around the worksite via a sidetrack (temporary road) or detour.  This method may also be the most expensive but would generally be considered on large projects. If the work is short term, then generally the traffic will be managed adjacent to or through the worksite.  Taking traffic through the worksite is usually the most hazardous.  If traffic will be travelling through the worksite, care must be taken by all works personnel to ensure the safety of people entering, leaving or in the worksite.

• Short Term Works -Works completed within a day – no need for signs overnight, usually managed adjacent to or through the worksite
• Long Term Works – Works taking longer than a day – need signs overnight. May also be managed via a detour or side track (temporary road) around the worksite depending on the nature of work

Careful consideration should be given to the signing of the work site, no matter how brief the occupation of the site may be. This should include:

• Adequate advance warning of workers & machinery.
• Adequate warning of changes in surface condition.
• Adequate Protection of workers.
• Adequate guidance through, past or around the work site.

2. Volume of vehicles

• Low Volume Road – Less than 1,500 vehicles per day
• High Volume Road – 1,500 or more vehicles per day

3. Speed of vehicles

• Low Speed Road -Traffic approach speed is less than 60 kph
• High Speed Road -Traffic approach speed is between 60 kph and 80 kph
• Very High Speed Road -Traffic approach speed is greater than 80 kph
• Vehicle Movements. (especially large vehicles) can have difficulty turning and maneuvering on sharp curves.
• Vehicle speeds. At 100kph a vehicle travels at approx. 28m per second and can take over 200 meters to stop.

4. Driver Consideration

• Driver Reaction. Drivers take time to react, can vary from 1 to 3 seconds. By the time a driver reacts, a vehicle may have traveled 80 meters.
• Drivers Eyesight. The driver of a vehicle needs to be able to read a sign from a distance. Signs should installed so they can be seen by the driver.
• Driver Expectation. Roadworks are not always expected by road users
• Credibility of Signs. Road users will only take notice of signs when they mean what they say.
• Worker Visibility. Workers have a responsibility to ensure they are visible to the road user.
• Night Conditions/Climatic Considerations. Signs and Devices need to be reflectorized so road users will see them. Rain and fog affects road visibility