Traffic diversions are provided for a safe and efficient movement of traffic through or around the work zones while protecting the workers and equipment deployed for road construction. In addition, they provide continuity to the movement of motor vehicles, bicycles, and pedestrian traffic, transit operations, and access to properties and utilities.
The diversion of traffic is majorly divided into two types.
1. Passage of Traffic on the Existing Carriageway under Improvement
- When part of an existing roadway is intended to be used for traffic passage, treated shoulders must be provided on the side where construction is not in progress.
- The shoulder must be treated with a minimum 150 mm thick granular base course overlaid with a bituminous surface dressing in a width of at least 1.5 m, and the surface must be maintained during the time it is utilized by the traffic.
- The continuous length in which the road works shall be carried out would be limited to 500 m at a place.
- However, where work is allowed in longer stretches, provision for overtaking shall be provided with additional paved width of 2.5 m at every 0.5 km interval.
- In case of widening existing two lanes to four lanes, the additional two lanes shall be constructed first, and the traffic is diverted to it, and further, the existing carriageway treatment shall be carried out.
- The treated shoulder constructed for diversion of traffic shall be dismantled, the debris disposed of, and the area cleared.
2. Passage of Traffic along with a Temporary Diversion
A temporary diversion shall be constructed in the road stretches where it is not feasible to let the traffic pass on the part of the carriageway. The temporary diversion shall be of 7 m carriageway and 2.5 m earthen shoulders on each side (total width of roadway 12 m) with the following provision for road crust in the 7 m width:
- 200 mm (compacted) granular sub base
- 225 mm (compacted) granular base course
- Premix carpet with seal coat/mix seal surfacing
The alignment and longitudinal section of diversion, including junctions and temporary cross drainage provision.
Traffic Safety and Control
- Before taking up any construction activity, an agreed phased program for the diversion of traffic on the highway shall be planned.
- All necessary measures for the safety of traffic during road construction shall be undertaken by providing/erecting barricades, including flags, lights, signs, markings, and flagmen for the protection and information of traffic passing through or approaching the section of the highway under improvement.
- The barricades shall be of a strong design to resist violation and painted with alternate black and white stripes erected on either side of the carriageway/portion of the carriageway closed to traffic.
- Red lanterns or warning lights shall be mounted on the barricades at night and kept lit throughout from sunset to sunrise.
- Places where traffic is required to deviate from its normal path, the channel for traffic, shall be clearly marked with the aid of painted drums or pavement markings.
- At night, the passage shall be illuminated with lanterns or other suitable light sources.
- When traffic must pass through a section of the highway that is insufficient for two-lane traffic, a one-way traffic operation must be formed. This will be accomplished with the assistance of temporary traffic signals or flagmen stationed on opposite sides at all times.
- The flagmen shall be equipped with green and red flags and lanterns/lights for traffic regulation.
- On both sides, suitable regulatory/warning signs shall be installed to guide road users.
- At least two signs shall be installed on each approach, one close to the point where the transition of the carriageway begins and the other 120 m away.
Maintenance of Diversions and Traffic Control Devices
Signs, barriers, lights, and other traffic control devices and the riding surface of diversions shall be maintained in a satisfactory condition until the diversion is used for traffic. The temporary path shall be kept free of dust by spraying water frequently.
FAQs
Traffic diversions are provided for the safe and efficient movement of the traffic through or around the work zones while protecting the workers and equipment deployed for road construction. In addition, they provide continuity to the movement of motor vehicles, bicycles, and pedestrian traffic, transit operations, and access to properties and utilities.
All necessary measures for the safety of traffic during road construction shall be undertaken by providing/erecting barricades, including flags, lights, signs, markings, and flagmen for the protection and information of traffic passing through or approaching the section of the highway under improvement.
The shoulder must be treated with a minimum 150 mm thick granular base course overlaid with a bituminous surface dressing in a width of at least 1.5 m, and the surface must be maintained during the time it is utilized by the traffic.
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