Hi, Welcome to OpenStreetMap.
It's difficult to discern the precise positioning of these highways as the imagery available to OSM as yet does not show the highways. What you've mapped is a very good start though. Perhaps you could correct/amend later when imagery of the new roads is available, (might be quite a wait).

One thing to note is that these two highways are islands not routable from Sywell Road as that is all tagged as construction. A highway under construction is not normally open to the public. I suspect that part of the road from Sywell Road to Lilac Way is open for public use. If so that section should have the construction tags removed and if possible be named.

Need any help please just ask. Regards Bernard.