Di Montezemolo is unhappy with the lack of overtaking at street circuits

Ferrari president Luca di Montezemolo has expressed his concern at the number of street circuits in Formula One.

Circuits in Valencia and Singapore have joined traditional street track Monaco on this year's F1 calendar.

But ahead of the inaugural Singapore race, Di Montezemolo said the lack of overtaking opportunities is not good for the future of the sport.

"I have the impression it will be one of those letdowns where you cannot overtake, like Valencia," he said.

606: DEBATE Are street circuits bad for F1?

The Grand Prix around the streets of Singapore on 28 September will be the first night race in the sport's history.