The Ring Road's Busiest Junction Goes Under the Diggers. Three Weeks Now, the Real Work in Spring 2027

The Road and Motorway Directorate has begun the first part of the capacity upgrade at the Třebonice interchange, the point on the south-western edge of Prague where the ring road crosses the D5 and the Rozvadov spur. Zdopravy.cz reports that what is happening now is preparatory only: the main construction is to start, according to ŘSD director general Radek Mátl, in the spring of 2027.

The junction is among the most heavily loaded and most traffic-sensitive places on the whole Pražský okruh. The last count put more than 75,000 vehicles a day through it, and queues form there routinely at the peaks. It sits on the Slivenec–Třebonice section, which opened on 20 September 1983 as the very first piece of the ring road to be built — a reminder that the junction now being widened is a design of the early 1980s carrying 2026 volumes.

Three weeks of groundwork

The preparatory phase is short and specific. By 13 October, temporary concrete crossovers are to be built on the D5 and on the ring road, so that traffic can later be switched onto the opposite carriageway. Alongside that, utilities are being relocated, cable routes laid for street lighting, foundations prepared for new sign gantries, and the existing crossover in the central reservation at the start of the D5 at Zličín removed. ŘSD expects this year's work to take just under three weeks.

Through it, both the D0 and the D5 keep two lanes in each direction. The speed limit drops to 80 km/h.

What the 568 million buys

The contract went to Silnice Group at 568.1 million crowns before VAT. It covers the reconstruction of three motorway bridges, the widening of slip roads on and off, and a further 37 smaller structures. ŘSD plans to finish the whole of what it calls stage 0 in 2028.

The point of the exercise is narrow and worth stating precisely, because "widening a junction" can mean almost anything. The capacity being added is on the branches between the southern arm of the ring road and the D5. The branch from the D0 onto the D5 is currently one lane and becomes two, and the branch running the other way becomes two lanes as well, which it is not today. Beyond that, the works are designed so that the D0 and the D5 can later be widened to three lanes in each direction without the junction having to be rebuilt again.

The seven kilometres next door

That last clause is not hypothetical. A separate scheme is being prepared to widen roughly seven kilometres of the D0 — section 515, between Třebonice and Slivenec — to three lanes each way. ŘSD is already rebuilding two overbridges this year, in advance, because the wider motorway would not fit underneath them as they stand. On the current programme the main six-lane works start in 2027 and finish in 2029.

Read together, the two schemes are one project in two contracts: a junction rebuilt to a standard that only makes sense if the road either side of it is widened, and a widening that only works if the junction is rebuilt first. The sequencing has the junction stage finishing in 2028 and the carriageway in 2029, which means the south-west corner of the ring road is a construction site for the next three years either way.