Is it permissible for pilgrims to depart from 'Arafat in stages to facilitate the departure of their increasingly great numbers?

The majority of scholars have concurred that:
• It is valid to stand at 'Arafat any time after zawal (midday).
• The time for standing there ends by the break of dawn of yawm an-nahr (day of sacrifice).
• It is valid to stand at 'Arafat for part of the day and night after zawal and there is no problem for a person who does this.

They differed on two issues:

1- The ruling for standing at 'Arafat and departing before zawal and whether this is a valid substitute for standing until after zawal.

The majority of scholars have maintained that this does not suffice and that whoever does so, must go back and stand on the plain of 'Arafat after zawal or spend a portion of that night until before dawn, otherwise he will have forfeited his hajj.

Hanbali scholars have maintained in their legal school that this suffices and that the hajj of a pilgrim who does so is valid.

2- Whether it is sufficient to stand on the plain of 'Arafat and depart before sunset.

Hanafi scholars and those who agree with them, consider it obligatory to stand at 'Arafat until sunset. The most valid opinion for the Shafi'is and those who agree with them is that standing at 'Arafat until sunset is recommended and not obligatory. They maintained that it is permissible for a pilgrim who was standing at 'Arafat before the sun has passed its zenith to depart before sunset.

Proponents of the second opinion on both matters substantiate their opinions with the hadith narrated by 'Urwa Ibn Madras (may God be pleased with him) who said, "I approached the Messenger of God at Muzdalifa when he was going for [the 'Eid] prayer and said, 'O Messenger of God! I have come from the mountains of Tayi`. I have exhausted my mount and worn myself out! By God, I did not come across any hill without halting there. Have I therefore accomplished my hajj?' The Prophet said, 'Whoever offers this prayer of ours, stands with us until we depart (and had stood at 'Arafat beforehand, whether by night or day), has accomplished his hajj and performed its rites " (recorded by Imam Ahmed and the authors of the Sunnan, Imams Bukhari, Muslim, At-Tirmidhi, Abu Dawud, Al-Nisa`i and Ibn Majah. At-Tirmidhi, Ibn Hibban, al-Darqutuni and al-Hakim declared it authentic).
After mentioning the hadith in Muntaqa Al-Akhbar, the Hanbali scholar Abu Barakat Ibn Taymiya wrote, "This is proof that the entire daytime of the day of 'Arafat is the time allotted for standing at 'Arafat.”
The ruling
It is possible for the responsible authorities to organize the departure and coming forth of the pilgrims from 'Arafat in a manner which suits their numbers and prevents overcrowding. It is permissible for them to make the pilgrims' departure in two or more stages, as required by their general welfare.

And God Almighty knows best.