Highways Agency

• 1. Introduction
• 2. Existing Conditions
• 3. Scheme Proposals
• 4. Engineering Assessment
• 5. Environmental Assessment - 1
• 5. Environmental Assessment - 2
• 5. Environmental Assessment - 3
• 5. Environmental Assessment -4
• 5. Environmental Assessment - 5
• 5. Environmental Assessment - 6
• 5. Environmental Assessment -7
• 5. Environmental Assessment -8
• 5. Environmental Assessment -9
• 5. Environmental Assessment -10
• 5. Environmental Assessment -11
• 5. Environmental Assessment -12
• 5. Environmental Assessment -13
• 5. Environmental Assessment -14
• 5. Environmental Assessment -15
• 5. Environmental Assessment -16
• 5. Environmental Assessment -17
• 5. Environmental Assessment -18
• 5. Environmental Assessment -19
• 6. Traffic and Economic Assessment

5. Environmental Assessment - 6

5.6 Summary and Conclusions

5.6.1 Existing Situation and Do Minimum

At present there are a large number of people affected by noise arising from theA14 between Ellington and Fen Ditton. There are almost 3,500 houses within 300mof the present route between these places and over 1,700 are affected by noiselevels from the A14 of 60dB or more. If no scheme is built, this will rise to over2,000 by 2010 and around 2150 by 2025.

OPTIONS AND ASSUMPTIONS

The assessment examined 3 general route options (Blue, Orange and Purple) plusa number of alternative variants to the west of Trinity Foot junction. To the east ofthis, a single option has been examined. The section to the east of the M11 wouldbe a widening scheme.

Simple 2m or 3m high environmental noise barriers or earthworks were consideredin the course of the noise modelling.

The EJS options considered the same basic routes but with different junctionstrategies. The LJS options were applied to some of the same routes. Both the EJSand LJS options considered some more substantial environmental barriers andbunds in order to improve noise mitigation.

All options assume quiet road surfaces.

The effects of noise changes in areas situated some distance from the A14 wherelevels are below 55dB has not been carried out at this stage. In order to make suchdeterminations with reasonable accuracy, it would be necessary to have furtherdata at locations where noise levels are low. It would also be necessary to havemore precise and certain data on road alignments and earth works.

General Effects of the Options

West of the A1 junction, there is little to choose between any of the options.However the Orange and the Blue / Purple options with the alternative A1 junctionsare favoured because there is likely to be more scope to mitigate noise increases.The Orange and Blue/Purple options are least favoured.

The Blue option would be within 300m of over 1,800 houses. Even with noisemitigation, could expose some sizable communities to significant increases in noisemainly because many of the areas are not presently exposed to high levels. Theareas most affected would be the south side of Brampton and the southern side ofGodmanchester with some risks of noise increases at Hilton, Conington and partsof the southern side of Fenstanton. The scheme would give overall benefits ofnoise reductions to about 580 to 680 people, depending on the junction strategy.

The Blue + Orange alternative would not cause significant increases in noise at thehouses in Brampton. There would be over 1,700 houses within 300m of it.However, there is some risk of some slight noise increases at Offord Cluny andparts of Buckden and Hilton. The scheme would give overall benefits of noisereductions to over 580 people or over 640 with the alternative junctions. Thescheme would give overall benefits of noise reductions to about 920 to 970 people,depending on the junction strategy.

The Orange route would remove the impact of noise at Godmanchester. Therewould be less than 1,600 houses within 300m of it. However, risks of noiseincreases remain at the quiet areas of Buckden and Offord Cluny with further risksat Hilton, an area where present levels are low. The scheme would give overallbenefits of noise reductions to about 820 to 840 people, but 800 or less with theLJS.

The Purple Route would have the same disadvantages as the Blue route atBrampton and Godmanchester. There are almost 2,000 properties within 300m ofit. However, by using more of the existing A14 corridor, it would be possible tomitigate further increases of noise to most of these with environmental barriers andthe disadvantages to Connington and Hilton would be avoided. The scheme wouldgive overall benefits of noise reductions to about 570 to 750 people, depending onthe junction strategy. There is no LJS for this route.

The Purple + Orange route combines many of the advantages of each. However,there would still be over 1,850 houses within 300m of it but many could bemitigated by barriers as above. The disadvantages of noise increases to the quietareas of Buckden and Offord Cluny would remain. The scheme would give overallbenefits of noise reductions to about 860 to just over 900 people, depending on thejunction strategy. There is no LJS for this route.

East of Trinity Foot there is a single route option which has been considered incombination with all options above. This could provide opportunities to mitigatenoise at most locations that are within 200 or 300m of the route. Some barrierswould provide significant reductions on present levels at those houses mostaffected. However, beyond that distance and where other roads have influence,noise levels may be increased due to the increased traffic, reduced congestion andlimited extent that barriers could reduce noise.

THE EJS AND LJS OPTIONS

The effects of the EJS options differ slightly to those described previously. As theroutes follow the same alignments, the numbers of properties within 300m of eachis the same. However, more substantial environmental barriers and bunds havebeen considered and some bunds would be up to 4m above the height of the road.Table 5.11 summarises the effects of all options in terms of changes in annoyance.

Noise Changes from Traffic outside the Present A14 and the Options

The construction of any of the options would bring about changes in traffic on thesurrounding network. This will lead to changes in noise not included in Table 6.21.In the case of the original Blue, Orange and Blue - Orange routes, this wouldamount to a 3 to 5dB increase affecting over 1,000 houses - approximately 2,400people. There would be similar decreases at 112 houses (almost 270 peopleaffected) and more than 10dB decreases at a further 114 houses (over 270 peopleaffected). In the case of the original Purple and Purple - Orange Options, over1000 houses would still get a 3 to 5dB increase. However, only 15 (36people)would get a decrease and this would be between 3 and 5dB.

In the case of the ESJ options, the Blue, Orange and Blue - Orange options wouldresult in 2,550 houses (over 6,100 people) experiencing a 3 to 5dB increase innoise. Decreases of 3 to 5dB would benefit over 200 (just under 500 people), 5 to10dB would benefit just 5 houses (12 people) and more than 10dB decreaseswould benefit almost 115 (over 270 people). In the case of the Purple and Purple -Orange ESJ route options, over 2,100 houses (over 5,100 people) wouldexperience a 3 to 5dB increase. Decreases of 3 to 5dB would benefit over 120houses (almost 300 people), over 10dB decreases at almost 110 houses (over 250people).

For the LJS options, over 2,500 houses (over 6000 people) would be affected by a3 to 5dB increase in noise. Decreases of 3 to 5dB would benefit just under 110 (justunder 260 people), 5 to 10dB would benefit just 5 houses (12 people) and morethan 10dB decreases would benefit almost 115 (over 270 people).