I believe the Hertford & Ware Urban Transport Plan is up for review this year.
The following paragraphs from the 2010 report are pertinent:
2.3.11 Whilst it is acknowledged that the A414 is a primary route that passes through the centre of Hertford, and there is peak time congestion associated with this road in the town, Hertfordshire County Council does not currently plan to construct a bypass. The UTP does, however, include a wide range of schemes and measures that will seek to help address the issue via the management of congestion and encouragement of walking, cycling and the use of passenger transport.
2.3.12 This UTP sets out short and medium term schemes over a five-year period but also includes longer term schemes up to 2021. Whilst a bypass is not included within this Plan as a longer term scheme, a review in five-years may involve revisiting potential bypass proposals. Should a bypass scheme gain support, implementation would be subject to funding and satisfactorily resolving other aspects such as establishing suitable routes and mitigating the impacts of any proposals.
The first paragraph is somewhat amusing (or naive depending on your view) in that it suggests that traffic passing through the town on the A414 might be mitigated by encouraging people to walk, cycle or use public transport. Not very helpful when the M25 is closed and the A414 is used as an alternative route.