Each one is two-lanes wide and normally carries traffic in a single direction. Plans to build a third tunnel have been abandoned. It was designed for horses and carriages and not for today's heavy traffic. It is also restricted on Tuesday evening and overnight for maintenance. There can be over-night closures and restrictions.
Delays can be long particularly in rush-hours and at weekends.
This week's road closures and roadworks in London including the Blackwall Tunnel closures. We welcome feedback and comments. Please read the legal page and data policy page. Awards and media coverage - credits page.