The car park below Place Guillaume II in the capital has been closed since 21 June for refurbishment works. A partial reopening was planned for November but has been postponed.
For a price of around €37m, the city will be adding around 250 parking spaces right at the heart of town.
Elsewhere in the country, the so-called RGTR bus network will change schedule from 12 December as part of a multi-phase overhaul of public transport in the country.
Changes began in May 2020 and a next round will come into effect on 12 December.
Four new services will launch: 404 between Mersch and Haller, 611 between Luxembourg and Noertzange, 629 between Troine and Troisvierges and 669 between Marnach and Bastogne in Belgium.
Dozens of lines will undergo adjustment, for example, changing stops or the frequency of services. A full line-up can be found online.