Commuters have found phone-based bus arrival information to be unreliable in recent months, despite claims by the Land Transport Authority that the system is now more accurate than before.

Bus spotter Tan Pang Soon, 26, said the problem started when the Land Transport Authority (LTA) integrated the arrival information systems of the two bus operators in April. "Previously, the (information) was quite accurate," said the fresh graduate, adding that the bus always arrived "within two minutes" of the stated time. But now, he said, the information is unreliable. He no longer uses the system.

Photographer Christopher Tan, 26, another transport enthusiast, had a similar experience. "In recent weeks, (information for) some of the services was not accurate," he said. "Recently, I was waiting for the No. 97 bus. (The information stated) it was arriving, but it had already left."

The glitch has caught the attention of blogger and satirist Lee Kin Mun, 45, better known as Mr Brown. In a recent post, he said the system had become "flaky" of late.

He said the system would say the bus was arriving in 20 minutes, but it actually arrived within a minute, or it would say a bus was coming in three minutes' time, but it had actually just left the bus stop.

Mr Lee's post, put up on June 29, drew responses from several readers, who cited similar experiences.

On Tuesday evening, Mr Lee said the system stated that services 107 and 107M had stopped operating - and it was only 8.15pm. He noticed that the glitches started to surface some time in April, when the LTA rolled out its arrival information platform, which includes seat availability on buses.

Field checks by The Straits Times at five bus stops yesterday found the system to be accurate in 19 out of 27 instances, giving it a success rate of 70 per cent. That is based on the number of buses arriving within three minutes of the stated time. If the error allowance is narrowed to one minute, the success rate plunges to 26 per cent. And if only buses that arrived on the dot were tallied, the system was only 15 per cent accurate.

Transport consultant Bruno Wildermuth said a bus arrival app "is useless as long as they don't publish a bus timetable".

"Then every day the bus arrives at a different time. There is no predictability and consistency," he said, adding that this made it hard for commuters to plan their day.

Mr Wildermuth, a regular bus commuter, said bunching still occurs regularly. Bunching refers to two or more buses of the same number arriving at the same time.

"This happens because buses arrive ahead of schedule," he said.

•Additional reporting by Cheow Sue-Ann