A28 Vollenhoventunnel gets extra weight in night works next week

Rijkswaterstaat, the national roads agency, will work on the Vollenhoventunnel on the A28 near Zeist on the evenings and nights of Monday 9 to Friday 13 November 2026. It is placing extra weight in the tunnel's central reservation (middenberm). The agency says the measure keeps the tunnel stable and safe and the A28 open to road users. The weight is meant to stop high groundwater levels in winter from pushing parts of the tunnel upward.

During the works, one lane in each direction stays open on the A28 at the tunnel. Work runs from 20:00 to 05:30 on weekdays and until 07:30 on Saturday 14 November. Rijkswaterstaat says road users should expect some delay, but that nothing changes for traffic compared with the current situation: the existing lanes stay open and the maximum speed remains 90 km/h.

The latest measurements show parts of the tunnel again moving slightly. According to Rijkswaterstaat, the central reservation is rising locally by a few millimetres, so the tunnel bulges slightly in the middle.

The same happened in early 2024, when measurements showed part of the tunnel rising a few millimetres. Research found the cause was a combination of a high groundwater level and damaged anchors in the pile foundation. Concrete blocks were then placed alongside the road for extra weight.

The tunnel has been closely monitored since late 2023, after problems at the Prinses Margriettunnel on the A7. Four structures of similar construction are monitored day and night. Only the Vollenhoventunnel showed movement.

Why it matters

• One lane stays open in each direction on the A28 at the tunnel during the five evenings and nights.
• Works run from 20:00 to 05:30 on weekdays and until 07:30 on Saturday 14 November.
• Rijkswaterstaat says road users should expect some delay.