Testing requirements
Before you begin the design phase, you must carry out appropriate site tests and investigations through a UKAS–accredited testing laboratory. All site testing during construction must comply with Kent’s latest Material Testing Requirements, which you can obtain from the Development Agreements Project Manager.
Standards and specifications
Roads are typically constructed in bitumen–bound materials, with a block–paved or bitumen–bound surface, and a foundation of granular sub-base and capping materials. Hydraulically–bound materials may be considered as an alternative foundation with our approval in certain circumstances. Footways are generally constructed in bitumen–bound, block paving or small–element paving materials; you may specify paving larger than 400 x 400 mm and other surfacing materials in appropriate locations, subject to approval. Where available all materials must have a CE mark.
Innovative materials and techniques
Where you propose to use non-standard materials, you will need to make a detailed proposal to the Asset Manager using our Technical Approval Process for Highway Assets. We strongly recommend you specify construction materials from sources that maximise the amount of recycled materials. For work in environmentally–sensitive areas, you should consult the local District Planning Authority early in the process to achieve good design solutions.
- Before you submit any proposals for approval, you must carry out a desk study, followed by a site geotechnical investigation, to identify issues including disposal of surface water run-off, subsoil drainage, earthworks and road thickness. You should agree the construction thicknesses with us before works commence.
- You must also conduct an environmental assessment to identify flora and fauna affected by the development and the steps required to protect and conserve them.
- All hard surfacing in the public realm needs to be fit for purpose: Surfacing defines people’s their view of the quality of construction and must be agreed on a site-specific basis. Any visible defects will require remedial works, at our discretion, before adoption.
- Block paved surfaces provide an attractive and practical alternative to flexible surfacing materials.
- We are happy to consider proposals using new and innovative construction methods and materials, on a case-by-case basis. Where this could result in increased future maintenance costs but are otherwise acceptable, you may need to pay a commuted sum.
- Kerbing protects pedestrians on footways, and verges from vehicle overrun; they also help direct surface water to gullies and define the inside edge on bends. You should specify kerbs only where necessary and in accordance with the development’s aesthetic requirements. Local District Planning Authorities may require special kerbs, such as granite–effect, exposed aggregate or granite setts, in conservation areas or to reinforce the location’s character and identity.
- All pedestrian crossings must be designed in accordance with the latest version of our Pedestrian Crossing Design Guide. Pedestrian crossing ramps with tactile surfacing must comply with the latest ‘Guidance on the Use of Tactile Paving Surfaces’ produced by the DETR.
- You must agree the layout of footways, footpaths and cycleways with us before the development is started. The layout should be sympathetic to pedestrians’ needs, with verges and planted areas carefully sited. All services must be are installed in accordance with the requirements of the New Roads and Streetworks Act 1991 before surfacing. The colour and type of surfacing materials used must clearly identify it as footway, footpaths or cycleway, and be agreed with us in consultation with the local District Planning Authority. Where necessary surface water run-off must be drained from footpaths and cycleways that do not abut the road.
