New World Athletics rules have been introduced to end the prospect of empty lanes in major finals such as last year's World Athletics Championship men's 100 metres ©Getty Images

Empty lanes following late withdrawals or disqualification will be a thing of the past thanks to rule changes established in time for the World Athletics Championships that started here today.

In another significant change, qualification in middle distance heats will be determined on positions rather than times.

The new rules, which follow widespread discussion with elite athletes and coaches, will mean that before finals and semi-finals next best-ranked athletes will be standing by in case any lanes need filling at the last minute.

Athletes in the "hot seats" will wait in a television room with cameras installed to allow spectators to witness reactions as lane changes occur.

Changes have also been made to the seeding of lane draws in track events after the first round.

For races in a straight line such as the 100 metres, while top-ranked athletes will occupy the four central lanes, the next best ranked will line up on either side of them, with the two last ranked athletes occupying lanes one and eight.

For the 200m the three best-favoured lanes are now five, six and seven, with the outside lane eight and lanes three and four being occupied by the next ranked runners, with the last-ranked running in the two inside lanes.

In the 400 metres event, the top-ranked athletes will go in lanes four, five, six and seven, the next-ranked athletes will slot into three and eight, with the rest getting one and two.

Previously, athletes running in the opening heat of middle distance events have been at a disadvantage as others then know how fast to go in order to secure the places available to fastest losers.

This system has now been replaced with qualification on positions.

For example, in the 1500m, there will be four preliminary heats where six athletes from each of the heats will proceed to the semi-finals irrespective of their finishing times.

In the semi-finals there will be two heats, where six athletes from each set will proceed to the final.

This will be applicable for the 1500m, 3,000m steeplechase and 5,000m.

There will also be leeway for runners who are ruled to have narrowly false-started - without being pinged by the World Athletics certified start information system - to run under protest.

"When the reaction time is close to the allowed limit (0.100), any movement may hardly be visible," World Athletics rule.

"Now in cases such as these, if the start referee feels the start in question requires further study, the referee may allow the athlete to run under protest."

The referee will make the final decision and relay it to stadium spectators and television audiences.

Any decision taken will be subject to appeal.