KHARTOUM - The yellow taxis of Khartoum were once an enduring part of its colonial legacy.

Now the vehicles, introduced in Sudan's capital under British rule in 1937 and last renewed as a fleet in 1978, bear the signs of numerous repairs, their paintwork chipped - and their often elderly drivers wait in vain for customers.

They say they've been left behind by competitors who advertise using unregulated ridehailing apps, and who drive newer cars.

"We've raised generations of children off the back of this taxi. But our taxis are old now," driver Alrasheed Ahmed, who has had his since 1980, told Reuters at one city cab rank with around two dozen vehicles.

"And now these app drivers have appeared and they just stick on a TAXI sign. That belongs to us and they're exploiting it," he added, gesturing towards a row of newer cars across the street.

The drivers' struggles mirror Sudan's wider economic decline, they say, with the government unable to finance new cars as fuel costs soar.

Some yellow cab customers remain out of loyalty. "There's no work at all. Some of them come here with a bunch of passengers and could wait until the sun goes down to leave with another... That is why I always ride with them," said one, Abbas Alamin.

But his gesture is a rare one, and even the ridehailing sector's future is far from guaranteed, with many Sudanese now choosing to forgo public transport altogether and rely on hitchhiking instead.

(Reporting by Eltayeb Siddig and Mohamed Nureldin Abdallah, writing by Nafisa Eltahir; editing by John Stonestreet)