Mae’r MIM yn cynnwys gofynion llym ynghylch rheoli effeithiau negyddol yn ystod y gwaith adeiladu megis sŵn, llwch a dirgryndod.  Mae’r contract hefyd yn cynnwys cyfyngiadau penodol ar reoli traffig wrth adeiladu’r ffordd, o ran nifer yr achosion o gau yr A465 a’r defnydd o ffyrdd lleol, gyda chosbau ariannol am beidio â chydymffurfio.
The MIM includes strict requirements around managing impacts during construction such as noise, dust and vibration. The contract also includes specific restrictions on the management of traffic while the road is being built, both in the number of closures of the A465 and the use of local roads, with financial penalties for non-compliance.