Traffic problems are predicted for Budapest tomorrow - and they have nothing to do with the broad avenues which dissect the ancient city by the Danube.

Because of the decision to cancel the semi-finals of the women's 5,000 metres, as many as 20 athletes, among them Sonia O'Sullivan, Una English and Valerie Vaughan, are now expected on the start line in the final (4.40 Irish time).

And that adds up to an additional worry for O'Sullivan as she contemplates the challenge of building on Wednesday's 10,000 metres win with another big performance in the Nepstadion.

"There's a fair chance of 20 people running, so the first priority is to get out of trouble - and then, as far as possible, stay out of it," she says.

"I hate being crowded - hate when there are lots of runners around me. True, it's not as big a problem in the 5,000 as in the 1,500 but if the early pace is slow, there can still be a lot of bunching.

"It means concentrating hard all the way but after running so well on Wednesday, there is no reason to believe that I will have problems in this area."

O'Sullivan's spectacular return to form, a recurring talking point among the media corps here, is already sending shock waves among her peers and yesterday it was confirmed that Fernanda Ribeiro will not run in tomorrow's race.

Ribeiro, troubled by a blood disorder earlier in the year, confessed to being totally drained after the 10,000 metres final and will now take a short break before resuming her Grand Prix programme.

The other big news to break yesterday is that Roberta Brunet, the silver medallist at this distance in last year's world championships at Athens, will not run because of an injury.

That, O'Sullivan concedes, should simplify matters marginally but there are still contingency plans to be drawn up for dealing with the threat presented by the talented Romanian, Gabriela Szabo.

No less than Ribeiro, Szabo has proved abrasive opposition in recent years, a point powerfully illustrated when she outpaced her more experienced rival in the final of the world 3,000 metres indoor championship at Paris in March of last year.

Later, with O'Sullivan embroiled in another crisis of confidence, the Romanian took the 5,000 metres title in the world outdoor championships in Greece to confirm her rating as one of the most exciting prospects to surface in years.

Curiously, she has yet to run a 5,000 metres race this season but O'Sullivan is not in the mood to attach too much significance to that. "She's had some very good 1,500 metres runs and anybody capable of running 8 minutes 24 seconds for the 3,000 metres is obviously in good condition.

"I respect her as a very good athlete and the one everybody has to beat on Sunday. But I think she may be looking at the race a little differently after what happened on Wednesday.

"At one point, she probably felt she had it all easy but if she watched the 10,000 metres, it probably set her thinking again. Now she may not be 100 per cent sure what she wants to do."

With a gold medal already banked, the tension has eased from O'Sullivan's face. It was much the same after she had won the first of her cross country tiles against the odds in Morocco and then returned the following day to do it all over again.

After a leisurely run in a suburban park yesterday morning, she spent the rest of the day relaxing, content in the knowledge that whatever happens tomorrow, she has already silenced her critics here.

"Anything else I get here, is a bonus," she said. "I go into the race knowing that I've nothing to lose and that doesn't happen too often in a big championship.

"I could have taken my medal, gone home and watched the race on television. But my attitude was that since I'm here, I may as well take my chance in it".

That smacks of sporting psychology at work. Szabo, the long range favourite for the title, has suddenly surrendered the high ground. And in the new, changed circumstances, O'Sullivan has suddenly assumed the aura of authority which was hers, almost by right for so long.

Bitter experience teaches that she hasn't always reacted well to the pressure of championship finals. But high on the improbability of Wednesday's win, she may now be primed for more heroics.