A proposal to increase a section of Germany’s autobahn to 10 lanes has campaigners concerned that it will increase carbon emissions and noise pollution, as well as causing the demolition of homes and biodiverse habitats.

The Autobahn 5 (A5) in Germany is one of the busiest highways in the country. Stretching 445km, it runs north to south from its junction with the A7 at Hattenbach to the Swiss border at Basel, closely following the Rhine.

As it passes through many major cities as well as Frankfurt Airport, the A5 is notorious for heavy traffic.

It is especially busy for 30km from a junction near Frankfurt Airport to the town of Friedberg to the north. This section is currently either six or eight lanes.

A proposal to increase the A5 has been laid out in a feasibility study commissioned by state-owned Autobahn GmbH, which manages the country’s motorways.

According to the study, this section of the A5 will see 200,000 cars driving on it daily by 2030. As such, the study suggests widening...