D3 motorway (Czech Republic)

D3 Motorway
Dálnice D3
Route information
Part of
Length97.4 km (60.5 mi)
Planned: 172 km (107 mi)
Major junctions
From D0 in Prague
To S10 border with Austria near Dolní Dvořiště
Location
CountryCzech Republic
RegionsCentral Bohemian, South Bohemian
Major citiesTábor, České Budějovice
Highway system
D 2 D 4

The D3 motorway (Czech: Dálnice D3) is a motorway in the Czech Republic. Once completed, the 172-kilometre-long (107 mi) motorway will connect Prague with the Austrian Mühlviertel Expressway (S10) to Linz. As of December 2024, only the middle section (97.4 km (60.5 mi)) of the motorway is in operation; namely a section from Mezno to Kaplice-nádraží. A further 15.5 km (9.6 mi) from Kaplice-nádraží to Czech Republic–Austria border is currently under construction. The D3 motorway is part of the European route E55.

The D3 motorway in the South Bohemian Region towards the Austrian border should be completed by 2026. Completion of D3 in the Central Bohemian Region is planned by 2028, however its designed course through the Lower Sázava landscape is still objected and opposed by environmental and citizens associations.

A nationwide trial of variable speeds of up to 150 km/h will begin on the D3 between Tábor and České Budějovice in summer of 2025, with factors such as weather conditions and traffic density influencing the maximum speed allowed.