Congestion at the Turkish straits is at its worst in at least 16 years, with the effects of tighter safety rules ­compounded by extra­ordinarily bad winter weather and a general ­increase in ship ­sizes, ­experts say.

Delays in the straits’ northbound and southbound traffic have amounted to 17 days so far this month — the longest total waiting time since records began in 2003, Clarksons data shows.