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Data Definitions

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Introduction

There are 3 types of definition as listed below:

· Road categories: Provides the definitions for the different road types used by the Department for Transport.

· Data table descriptions: Provides the data item name, the label name and a data description for the data sets that can be downloaded from this web site. The data includes network and annual average daily traffic flows.

· Look-up table descriptions: Shows the data item name, heading label and data description for the look-up tables for the local Highway authority, the regions and the road categories.

Look-up tables

· Look-up table values: Lists the local Highway authorities, the regions and the road categories in the look-up tables.

Road Classes

· Major roads: Include motorways and A roads. These roads usually have high traffic flows and are often the main arteries to major destinations.

· Motorways: Major roads often used for long distance travel. They are usually three or more lanes in each direction and generally have the maximum speed limit of 70mph.

· A Roads: Can be trunk or principal roads. These are often described as ‘main’ roads and tend to have heavy traffic flows though not as high as motorways.

· Trunk roads: Most motorways and many of the long distance rural A roads are trunk roads. The responsibility for their maintenance lies with the Secretary of State and they are managed by the Highways Agency in England, the National Assembly of Wales in Wales and the Scottish Executive in Scotland (National Through Routes).

· Principal roads: These are major roads maintained by local authorities. They are mainly A roads (though the local authorities do have responsibility for some motorways) and tend to be in urban areas.

· Minor roads: These are B roads, C roads and unclassified roads and are all maintained by the local authorities. Data for minor roads are unavailable.

· Urban roads: Major and minor roads within an urban area, i.e. an area with a population of 10,000 or more. The urban areas used are based on 2001 Census data. The definition is based on the 2001 'urban settlement' and is available in Urban and rural area definitions: a user guide which can be found on the DCLG web site at:

http://www.communities.gov.uk/planningandbuilding/planningbuilding/planningstatistics/urbanrural/

· Rural roads: All other roads, i.e. those outside urban areas (urban areas having a population of 10,000 or more - see above).

Measures of traffic

· Count Point (CP): Traffic estimates are calculated for each link of Great Britain 's major road network, with links' start and end points defined as where the link joins a major road junction. Each link has a uniquely referenced Count Point (CP), where the traffic is usually counted by enumerators. Enumerators are not employed where (a) the CP is dependent upon another CP, i.e. the traffic estimate is calculated for each side of a Local Authority boundary, or (b) the traffic estimate is derived from neighbouring CPs' traffic estimates. Unlike the major road network (where every link has a CP), there are CPs on a sample only of minor roads.

· Annual Average Daily Flow (AADF) - measured in number of vehicles: The average over a full year of the number of vehicles passing a point in the road network each day.

· Traffic - measured in vehicle kilometres: One vehicle times one kilometre travelled (vehicle kilometres are calculated by multiplying the AADF by the corresponding length of road). For example, 1 vehicle travelling 1 kilometre a day for a year would be 365 vehicle kilometres. This is sometimes known as the volume of traffic.

Data Table Descriptions

Major Roads Network

Data item name	Heading label	Description
LACode	LACode	Local Highway Authority (Administrative) code number - unique reference. See the look-up table LACode below.
CP	CountPoint	Count point reference number (UNIQUE).
dOpened	dOpened	Date road link opened.
dClosed	dClosed	Date road link closed.
Road	Road	Road classification number.
RdSeq	RdSeq	Road sequence number.
RCat	Category	Road category at count point. See the look-up table RCat below.
LenNet	Length	Total length of network road link - kilometres.
SRefE	CPEast	OS grid reference at site of count point: Easting - British National Grid.
SRefN	CPNorth	OS grid reference at site of count point: Northing - British National Grid.
Closed	Closed	Indicator - road closed or reclassified as minor road.

Annual Average Daily Flows (AADF)

Data item name	Heading label	Description
CP	CountPoint	Count point reference number (UNIQUE).
Year	Year	The year of the last traffic count.
FdPC	Bicycles	AADF: Pedal cycles.
Fd2WMV	M'cycles	AADF: Two wheeled motor vehicles. Includes motorcycle combinations, scooters and mopeds.
FdCar	Cars	AADF: Cars and Taxis. Includes estate cars, light vans with windows to the rear of the driver's seat, passenger vehicles with 9 or fewer seats, three-wheeled cars, motorised invalid carriages, Land Rovers, Range Rovers and Jeeps. Cars towing caravans or trailers are counted as one vehicle.
FdBus	Buses	AADF: Buses and Coaches. Public service vehicles and works buses, which have a gross vehicle weight greater than 3,500kgs.
FdLGV	Vans	AADF: Light Goods Vehicles. Goods vehicles up to 3,500 kgs. gross vehicle weight. Includes all car-based vans and those of the next larger carrying capacity such as transit vans. Also included are ambulances, pickups, milk floats and pedestrian controlled motor vehicles. Most of this group are delivery vans of one type or another.
FdHGVR2	HGVr2	AADF: Rigid 2-axle Heavy Goods Vehicles.¹
FdHGVR3	HGVr3	AADF: Rigid 3-axle Heavy Goods Vehicles.¹
FdHGVR4	HGVr4	AADF: Rigid 4plus-axle Heavy Goods Vehicles.¹
FdHGVA3	HGVa3	AADF: Articulated 3 or 4-axle Heavy Goods Vehicles.¹
FdHGVA5	HGVa5	AADF: Articulated 5-axle Heavy Goods Vehicles.¹
FdHGVA6	HGVa6	AADF: Articulated 6plus-axle Heavy Goods Vehicles.¹
FdHGV	HGV	AADF: Heavy Goods Vehicles total.¹
FdAll_MV	AllMV	AADF: All Motor Vehicles total.

Footnote:
1. Goods vehicles over 3,500 kgs gross vehicle weight. Includes tractors (without trailers), road rollers, box vans and similar large vans. A two axle motor tractive unit without trailer is also included.

Look-up table descriptions

LACode - Local Highway Authority

Data item name	Heading label	Description
RegG	RegNo	Regional Office number. See the look-up table Region below.
LACode	LACode	Local Highway Authority Code number.
LName	LocalHighwayAuthority	Local Highway Authority name.

Region - Government Office Region

Data item name	Heading label	Description
RegG	RegNo	Regional Office number.
RName	Region	Regional Office name.

RCat - Road category

Data item name	Heading label	Description
RCat	Category	Road Category (at Count Point if on Link).
RCatName	CategoryDescription	Road Category description

Look-up table values

A complete list of lookup values relating to the LACode, Region and RCat tables are contained in the accompanying attachments at the top of the webpage.