Aggregate Abrasion Value (AAV)

the standard measure of an aggregate's resistance to abrasion.


unless otherwise stated, in this Specification and Definitions, 'the Authority' refers to the Authority as defined in the Act.


British Board of Agreement/Highway Authorities Product Approval Scheme - a recognised body giving approval for products and processes.

Bond Coat

Bond coats are proprietary materials certified by HAPAS, generally formulated to enable heavier application rates than are possible with tack coats and to provide greater cohesion between bituminous layers.


Cement Bound Granular Material.


Californian Bearing Ratio: a measure of the load bearing strength of a granular or unbound material.

Composite construction

a structure where the road is composed of lean mix concrete or other cement bound granular material, normally with bituminous surfacing layers.


see 'stepped joint'.

Cycle track

a road where the public right of passage is by pedal cycle only, or by pedal cycle and foot only.

Deep openings

all excavations and trenches in which the depth of cover over the buried apparatus is greater than 1.5 metres. Trenches with a depth of cover that is intermittently more than 1.5 metres for lengths of less than 5 metres are not deemed to be deep openings.

Emergency works

works whose execution at the time when they are executed is required in order to put an end to, or to prevent the occurrence of, circumstances then existing or imminent for which the person responsible for the works believes on reasonable grounds to be existing or imminent which are likely to cause danger to persons or property.

Flexible construction

a structure where the Base is composed of either bituminous material or granular material, or a combination thereof.


a way over which the public have a right of passage on foot only, not being a footway.


a way comprised in a road, which also comprises a carriageway, being a way over which the public have a right of passage on foot only.

Geosynthetic materials

a generic term describing a product at least one of whose components is made from a synthetic or natural polymer, in the form of a sheet or a 3D structure, used in contact with soil and/or other materials in geotechnical and civil engineering applications.


Hydraulically Bound Materials.


Highway Design Standard- A section of the Design Manual for Roads and Bridges (DMRB) issued by the Stationery Office - Standards for Highways.

Immediate Reinstatement

works comprising the orderly replacement of excavated material reasonably compacted to finished surface level, usually with a cold-lay surfacing.

Interim reinstatement

the orderly placement and proper compaction of reinstatement layers to finished surface level, including any temporary materials. Also including the ancillary activities in S11.1.1 before opening the works to traffic


restoration of a reinstatement which does not comply with the performance standards, to a condition complying with those standards.


Los Angeles Abrasion Value - measure of the resistance to abrasion of an aggregate.

Major projects

standard works which have been identified specifically in the Undertaker's annual operating programme or which, if not specifically identified in that programme, are normally planned at least 6 months in advance of works commencing.

Modular construction

a structure where the surface is composed of setts, concrete blocks, brick pavers or paving slabs etc. laid on appropriate sub-construction.


million standard axles.

Narrow trenches

all trenches of 300 mm surface width or less, with a surface area greater than 2 square metres.


the penetration grade of a bituminous binder.

Permanent reinstatement

the orderly placement and proper compaction of reinstatement layers up to and including the finished surface level. Also including the surface requirement in S6.4 and ancillary activities in S11 with permanent materials


An allowable alternative to the preferred material - see also 'Preferred'.


The favoured choice between a number of options - see also 'Permitted'.


Polished Stone Value.


Pendulum Test Value - a measure of the frictional properties of a surface using a Pendulum test device.

Rigid construction

a structure where the surface slab also performs the function of the Base; is of pavement quality concrete and may be reinforced. Under certain circumstances, as defined in Section S7, a rigid road that has been overlaid may be deemed to be a composite construction for the purpose of this Specification.


the whole or any part of any of the following, whether or not there is over it a public right of passage and whether it is for the time being formed as a way;

any way (other than a substitute road made under section 74(1) of the Roads (Scotland) Act 1984 or a waterway)

This includes any square or court.

and for the avoidance of doubt includes land on the verge of a road or between two carriageways. Where a road passes over a bridge or through a tunnel, references to the road include that bridge or tunnel. (NRSWA section 107 etc.).

Road & footway structure

includes the surface course, binder course, base and sub-base.

Road Manager

Ref. New Roads and Street Works Act Section 108 (4).


Specification for Highway Works, published as Volume 1 of the Manual of Contract Documents for Highway Works (MCHW1) Standards for Highways.

Small excavations

all openings with a surface area of 2 square metres or less. For the purposes of this Specification, test holes up to 150 mm diameter are not excavations and shall be reinstated in accordance with the requirements of Section S11.


Skid Resistance Value - a measure of the frictional properties of a surface using a Pendulum test device.

Stepped joint

the practice whereby the width of the reinstatement of the binder course and/or surface course is made wider than the reinstatement below it to provide higher resistance to water ingress.

Tack Coat

Conventional bitumen emulsions conforming to BS EN 13108 classes C40B4 or C60B3 used to enhance the adhesion of the overlying bituminous layer which might be impaired due to minor dust problems or insufficient free bitumen on the surface of the layer to be overlaid.

The Act

unless otherwise stated in this Specification and Definitions, 'the Act' refers to the New Roads and Street Works Act 1991.

Traffic sign

has the same meaning as in the Road Traffic Regulation Act 1984.


The cut face that defines the outer edge of an excavation.


The area between trim-lines excavated around a fixed feature to permit adequate reinstatement.


Transport Research Laboratory.


the organisation that has introduced a national scheme for the accreditation of Laboratories used for the testing of materials.


unless otherwise stated in this Specification and Definitions, 'the Undertaker' refers to the Undertaker as defined in the Act and is the person in whom a statutory right to execute works is vested or permission under section 109 to execute road works.

Urgent works

works which fall short of emergency works but are of sufficient urgency to warrant immediate action either to prevent further deterioration of an existing situation or to avoid an Undertaker becoming in breach of a statutory obligation.


that part of the road outside of the carriageway, which may be slightly raised but is exclusive of embankment or cutting slopes, and generally grassed.

Wheel Tracking

A test to determine the resistance to deformation (rutting), primarily of surface courses.