|Distance:||5.8 miles (9.3 km)|
|Meets:||A199, A1140, A199, A6095, A1, A720, A6106|
|Route outline (key)|
The B6415 is a V-shaped road of two halves east of Edinburgh. It provides a "long way round" route from Portobello to Millerhill via Musselburgh, avoiding the A6106. The east-west section was originally the A1 whereas the north-south section has been the B6415 since it was upgraded from an unclassified road around 1930.
Starting at a signalised junction on the A199 and A1140 in the Edinburgh suburb of Portobello we head southeast along Portobello High Street, the original route of the A1. We skirt the Firth of Forth as we pass through Joppa and soon reach traffic lights back on the A199. There's a multiplex ahead along that road for about half a mile into the Musselburgh suburb of Newhailes, where the B6415 regains its number at traffic lights and runs down Newhailes Road to a roundabout and another multiplex with the A6095; this avoids an earlier route through the town centre along Market Street and Campie Road.
The B6415 reappears by the bridge over the River Esk and heads upstream, gaining a more rural character. After going under the East Coast Main Line we reach a roundabout where a road bears left to the A1/A720 junction (and is signed as being part of both those roads, or as the primary B6415 in the other direction). We then go under the A1 and out along a fairly straight piece of road into Millerhill. Originally the road continued straight to end at a roundabout on the A6106 but that road's route was severed here when the Borders Railway was built; as such we bear right in Millerhill then left over the railway to end at a different roundabout.