Living Highways

Promoting a wide variety of species and plant-life – biodiversity – is a priority for conservationists, especially in order to protect species that are threatened by habitat loss, pollution and climate changes, pollution. Road verges can be remnants of original habitat or created as new habitats in the urban environment. They are linear habitats which can connect other larger areas of habitat as part of ecological networks.  How they are managed can have a big impact on the diversity of plants, invertebrates and other wildlife that they can support.

The Sheffield Living Highways project was a collaborative project involving Sheffield and Rotherham Wildlife Trust, the University of Sheffield, Sheffield City Council and Amey 2015-2019. Its aim was to trial whether changes to the management of the city’s grass verges can have a positive impact on the city’s ecosystems.

Amey is responsible for the maintenance of 2.9 million metres² of road side verges in Sheffield as part of the ‘Streets Ahead’ contract. Most of these verges are areas of regularly mown grass, but they also include some rural verges, shrubs and small patches of green space.  The ‘Streets Ahead’ contract is very specific about how these verges should be managed with a focus on the frequency of the mowing cycle and the height of the grass sward; however, over the last few years, The Sheffield Living Highways Project partners looked at whether changes to the way the verges are managed, such as leaving it to grow longer, replacing some grassed areas with wildflowers, and introducing native hedgerows or trees, could increase the biodiversity value of these habitats.

Results and lessons learnt

Mowing Trials

In 2016 and 2017 a mowing trial was conducted on 17 urban roads in Sheffield. On one side of each road, mowing proceeded as normal (every 3-4 weeks) but was reduced by half on the other side of the road (every 6-8 weeks) during the entire mowing season (April – October). Grass cuttings were left on grass verges after mowing took place. Plant and insect surveys were conducted by the University of Sheffield on these trial roads to measure the impact on biodiversity. Roads were a mix of residential streets and non-residential key transport links. The mowing trial was communicated to the public through a press release, signs on lamp posts and leaflets delivered to every house on the mowing trial roads. Research also examined the public perception of the mowing trial;

Results showed many local residents do not always like the appearance of unmown grass, meaning it is not always appropriate just to let grass grow longer directly outside people’s houses. However there was some appreciation that it is better for biodiversity.

Trial sites 

Bochum Parkway
This road verge was shown to support remnants of floristic diversity, but was being mown too frequently for the flowers to display.

A stretch is now subject to less frequent mowing and this has been successful in allow the herbs and grasses to flower. In 2019, yellow rattle seed was applied by S