New towns generally mean new road numbers, but this isn't the case with the A899. Instead of creating a whole new number, the A899 was turned through a right angle and extended out of zone, almost doubling in length at the same time.
West Main Street, Broxburn
The road begins on the A89 at Kilpunt Roundabout, forking right along the original line of the A8 through Broxburn. The A89 along the original Broxburn Bypass is itself also a former line of the A8, and the opening of the bypass saw the A899 number coming in to use in the mid 1930s. The road runs along Main Street, past the junction with the B8020 and on through the middle of town, past all of the shops and other town centre services, through a variety of flat junctions including a signalised crossroads, yellow boxes, turning lanes and normal urban T junctions. Once through the town centre, the road runs out through a seemingly endless line of Victorian villas and terraces, almost unnoticeably crossing the Union Canal and on into Uphall, the once separate towns now merged together.
In Uphall, the B8046 enjoys a short multiplex westwards, after which the A899 finds its first section of 'countryside', although in reality the avenue of mature trees hides the Golf Course beyond. The road is wider here, now it has escaped the confines of the town, or maybe it just feels wider without rows of parked cars. At a mini roundabout, the A899 turns off its original course, which continued ahead as a spur for several years, and heads south to Dechmont Roundabout. Here it crosses the A89, becomes dual carriageway and quickly passes under a sliproad from the M8. After crossing the mainline of the motorway, it meets M8Junction 3, a free-flowing pseudo-trumpet that halts on a roundabout almost right away. Only three of the sliproads meet the roundabout, the eastbound on slip forking off the A899 just north of the bridge over the motorway. A small service area and business park are also accessed from the roundabout.
Aerial view of Cousland Interchange
Continuing south, the dualled A899 cuts a straight line through trees, which just about hide the houses and industrial estates of Livingston to either side. The former cloverleaf junction of Houston Interchange is passed with a break in the trees. The A899 clearly has a love for the unusual in junction design however, as the next junction, Cousland Interchange, is one of only two remaining complete cloverleafs in the country. The A705 starts here, heading west on another completely new route through the new town. The trees resume as the road takes a long gentle descent to cross the River Almond, passes through Centre Interchange, which gives access to Livingston's Town Centre, and then climbs a little to its terminus on the A71 at Lizzie Brice's Roundabout.
The road from Burnside to Dechmont through Broxburn and Uphall was numbered A8 in 1922, whilst the road to the south (the current A89) did not exist. It is marked as having Class I status, albeit unnumbered, on the 1932 Ten-Mile Map and soon became the A8 itself, with the old road becoming the A899 by 1936. Although this renumbering occurred in the mid-1930s it is not known if it was part of the 1935 renumbering.
The construction of the New Town of Livingston in the 1960s required a new dual carriageway spine road for the settlement; this appears to have been the A899 from the beginning, despite taking the number out of zone. This gave the A899 a spur through Dechmont, which has since been declassified.
Stage 1 from A8Dechmont Roundabout to Houstoun Road opened in November 1967. Width was 126 feet with 24 foot dual carriageways.
Stage 2 from Houstoun Road to Almond Road had opened by September 1968.
Stage 3 from Almond Road to A71 south-west of Mid Calder opened on 28 February 1972. It included a 1000 foot long and 60 feet high Almond Valley Viaduct over the River Almond. Cost was £510,000. This completed the Livingston "Spine road" between A8 and A71.