A decision on plans for more than 1,700 new homes in a Somerset town could be delayed for at least six months following warnings by transport bosses.

Outline plans for the Selwood Garden Community (SGC) have been put forward, which would see green fields between the A361 and the Frome's southern edge transformed into a substantial new community.

Land Value Alliances, acting on behalf of the SGC landowners consortium, has promised the development will also deliver new employment sites, a primary school and other facilities for both the new community and existing residents.

But National Highways – which manages major roads across Somerset – has now called for a decision on the plans to be pushed back on the grounds that a key route between Frome and Bath may not be able to cope with the additional traffic.

While most of Somerset's roads are the responsibility of the county council, National Highways is responsible for a number of strategically important main roads – including the A303, the M5 and the A36.

Where new development could impact on the smooth operation of any of its roads (e.g. by increasing traffic and the possibility of congestion), National Highways can issue a "holding recommendation" – essentially an instruction that no new homes or other development can be granted on a given site until its concerns have been addressed by the developers.

One such recommendation is currently in place regarding Junction 23 of the M5, with National Highways requiring that the Dunball roundabout near Bridgwater be improved before any further sites for housing or employment in the surrounding area can be unlocked.

To lift the holding recommendation, Somerset County Council is to upgrade the Dunball roundabout into a "throughabout" to improve traffic flow, using money from the government's levelling up fund, the Bridgwater town deal and Sedgemoor District Council (among others).

National Highways planning manager Lisa McCaffrey said any decision on the SGC proposals in Frome should be delayed for at least six months until more work had been carried out to show the new homes would not lead to disruption on the A36 leading to Bath.

She said: "We issued a holding recommendation requesting additional assessment be undertaken to enable us to determine the impact of the development on the safe and efficient operation of the A36 and its junctions.

"We are currently working with the applicant's consultants to progress the necessary transport assessment work, and to enable this work to be completed are extending our current holding recommendation by an additional six-month period."

The southern edge of Frome is expected to deliver large amounts of new housing in the coming years, with multiple sites being identified by Mendip District Council within its Local Plan Part II, which was ratified in December 2021.

The council's planning board granted permission in February for 249 homes either side of the B3092 The Mount, along with 198 homes either side of Sandys Hill Lane.

Plans for a further 70 homes between the B3092 and Little Keyford Lane are currently being considered, with a decision expected later in the spring.

The SGC site is not included in the Local Plan Part II, except for a small section on the northern side of Little Keyford Lane which is earmarked for 20 homes.

With the National Highways restriction in place, a decision on the SGC plans will not be taken until the autumn at the very earliest.