Helsinki’s new Crown Bridges megastructure reveals safety flaw as cyclists demand fixes

Cyclists in Helsinki are calling for urgent repairs to Finland’s newly opened Crown Bridges after a potential hazard was identified in the structure’s expansion joints, reports Finnish public broadcaster Yle.

The issue involves three-centimetre-deep depressions at both ends of the 1.2-kilometre Kruunuvuorensilta (Crown Bridges) bridge, where movement joints create abrupt drops in the cycle path. Cyclists warn that the uneven surface—particularly when descending from the bridge’s elevated centre—risks causing front wheels to jam, leading to crashes.

Henni Ahvenlampi, executive director of the Helsinki Region Cyclists association, described the joints as “still unfinished,” noting they could damage bicycles and pose a falling hazard. “They jolt riders and may break bike components,” Ahvenlampi said, urging the city to implement fixes for safe, smooth cycling. While she praised the bridge’s overall design, she admitted to crossing cautiously during Saturday’s opening parade, maintaining speeds of 15–17 km/h—slower than her usual pace.

City acknowledges “challenging” design but rules out changes

Marko Jäntti, Helsinki’s project director for the Crown Bridges, confirmed the joints were a known “challenge” but dismissed claims they posed a direct danger. The gaps, he explained, are unavoidable due to the bridge’s thermal expansion requirements—its steel components contract in cold weather, necessitating over half a metre of flexibility.

“The protective plate over the joint is 25 millimetres thick, so a three-centimetre depression is inevitable,” Jäntti said, adding that the site was marked with coloured strips for visibility. He observed cyclists navigating the area “without major issues” during his visits, though some participants in Saturday’s 1,800-strong opening parade had already placed warning signs near the joints.

The bridge, now Finland’s longest at 1.2 kilometres, recorded over 50,000 crossings in its first weekend. Connecting eastern Helsinki to the city centre, it opened to pedestrian and cycle traffic amid celebrations on Saturday, drawing both cyclists and walkers in sunny weather.

Discussions about the joints’ safety have since spread across social media cycling groups, with some riders suggesting additional warning signs.