They support fragments of the type of flower-rich grassland once widespread in lowland Britain.
Managed well, the verges can support a wide range of plants and animals. With around 10,000km of highways in Hampshire, this presents approximately 13,000 hectares of roadside verge habitat, equivalent to 3% of the county's land area.
The County Council is responsible for the management of the verges on all roads in the county, except motorways, major trunk roads, and urban areas. Approximately 15 to 20 RVEIs are surveyed each year by HBIC as part of an annual survey programme to assess their value for biodiversity.
To qualify as a Road Verge of Ecological Importance (RVEI), the verge must support either a notable species and/or a species rich habitat. Selection of RVEI sites is undertaken by the Hampshire Biodiversity Information Centre (HBIC).
Plants need to remain uncut throughout their flowering and seeding seasons so they can survive and reproduce. Conventional cutting that takes place throughout the summer can be destructive. It can eventually result in plant extinction. This means that most RVEI verges are cut in April or late September.