Page:UK Traffic Signs Manual - Chapter 8 - Part 1 (Traffic Safety Measures and Signs for Road). Designs 2009.pdf/65

DESIGN CRITERIA

In order to achieve rapid removal of broken-down vehicles, it is essential that an efficient system is set up to monitor the affected network for broken-down vehicles throughout the duration of the works. This can be achieved using one of the following.

Closed Circuit Television (CCTV) — such systems are relatively expensive to install and maintain but are reliable and allow 24 hour monitoring and recording of the affected network. CCTV systems can be linked either directly to the recovery contractor’s office or else to a dedicated monitoring station provided by the main contractor. Monitoring stations should be manned for the duration of any restrictions imposed by the works and should be provided with appropriate communication systems; see also Section D3.37.

Dedicated roving patrols — these patrols offer a cheaper alternative in terms of set-up costs. They require additional recovery or contractor’s staff to drive through the works area looking for broken-down vehicles. Once found, the patrol reports the location to the recovery base. Unless the dedicated roving patrol vehicles are fitted with an approved lorry-mounted crash cushion (LMCC), they should not be used to protect broken-down vehicles. The specification for LMCCs can be found in TD 49 " Requirements for lorry-mounted crash cushions" (DMRB 8.4.7). On largersites the use of dedicated roving patrols can slow the recovery operation when compared with CCTV and hence this system is not recommended for road works where congestion is currently or likely to become a major problem.

Watchman — providing a watchman is the cheapest of the three systems and relies upon contractor’s staff within the site area acting as lookouts for broken-down vehicles. This system can be very effective within small sites but has limited value on larger sites. Watchmen can be useful when used in conjunction with dedicated roving patrols.

The level of recovery service employed should be appropriate to the risk of accident and/or the scale of congestion likely to develop.

Dedicated/on site recovery equipment — this is a costly option as the recovery vehicles and staff are based on site permanently for the duration of the works or restrictions. Response times will be dependent upon the size of site and number of bases but are usually quicker than any other arrangement.

Watchmen/local arrangements — this system is reliant upon there being locally based recovery services available. The contractor shall make arrangements with a local service provider for a priority call-out system. The required service level including response times and minimum equipment levels should be specified by the designer.

The designer should ascertain that there are suitable locations for a recovery base station in consultation with emergency services and adjacent highway authorities. However, the final choice should normally be left to the contractor unless there are particular safety implications that could limit the number of suitable locations.

When choosing the location of the base, designers and contractors should give consideration to the safety of both the recovery operator and the road user. Recovery vehicles should not be required to carry out dangerous manoeuvres on the network in order to enter or exit their base. If located adjacent to the carriageway they should be suitably protected from accidents involving errant vehicles or debris. The use 64