Mongolia
Ulaanbataar, 2005
large, 14 MB
Ulaanbataar, 2009
large, 2 MB
So, I think we can establish there are major developments in Ulaanbataar. But what about the roads?
Some Mongolian news sites, like this one below, reported the paved highway you've highlighted, as "A18"Another thing I've come across with the Mongolian road network.
The road classification was introduced in 1998, older JICA reports also contain a route numbering that still seem to exist today (same as on OSM), so I suppose the route numbering is also from 1998.
Part of the route numbering is A18, a 578 kilometer east-west route in northwestern Mongolia, from Tsagaan-Uul to Ulaangom. This was probably planned to become a paved road.
However they later decided to pave an unnumbered route farther south, from Tosontsengel via Numrug to Ulaangom. This was completed in 2019:
Auto road connecting Uvs aimag with Ulaanbaatar city opens
Ulaanbaatar /MONTSAME/. The Ministry of Road and Transport Development reports that a construction of 135.7 km auto road along the Songino-Khyargas Lake in Uvs aimag was commissioned, connecting the aimag with the capital city.montsame.mn
Here's a map of both routes (don't get fooled by the unfamiliar placenames, this map spans over 1,000 kilometers west to east).