If you're considering crossing this border you might be interested in reading my post about security situation in Pakistan/Balochistan
I crossed the border on January 8 (Monday).
I had arrived in Zahedan (hitch-hiking) on January 6 (Saturday) and slept in a park. At sundown on January 7 I decided to start walking towards the border and find a safe-ish place to sleep out so I could start hitching the next morning already out of Zahedan. The idea was to avoid running into the police and getting the escort. On the way out of Zahedan a man spontaneously offered me a ride out of town on his bike. When he suggested bringing me to a hotel, I told him I had no cash and wanted to continue walking. As I was trying to get him to understand me a police man popped up and I was not sure what they told each other, but I wasnt asked for my passport or asked any question. When the police man left, the driver insisted on me following him to the hotel and I thought he would negotiate for me to sleep in the yard as it was pretty huge and empty. I ended up being treated a room by the hotel management. The next morning I checked out at 6.30 and I was told to wait for police escort and offered breakfast. Could not think of a better way to say goodbye to lovely Iran
We changed cars in total 5 times, including one ride from a car the police had stopped and asked to give me a lift, and one from a truck in the same manner. We waited around for up to 45 min between escorts. At all times my passport was moving between officer's hands and not in my own. At one point the border police had no vehicle to escort me and called a taxi and asked me to pay for it. I had the struggle of my life convincing them that I was genuinely out of cash and only had enough to buy my train ticket out of quetta, and in the end I think they still didnt believe me (the taxi driver had left looking at me like a total cheapskate), but they agreed to stop a truck for me.
I arrived at the border around 11.30 am.
For the rest of the story in Balochistan, it's pretty much same as mentioned before. Stayed over at the border, the levies offered food somehow reluctantly (lunch and dinner, no breakfast), so I would recommend bringing some supplies.
Also I suspect bringing passport photocopies (as suggested above) would have been useless. It seemed like at each stop the officers wanted you to enter your details in their register by hand and I suspect many of them were not good with latin characters.
Temperatures in the night dropped to 0 or negative 1 and while in the back of pickup trucks the wind was quite chilly even in mid-day sun. If crossing in the winter bring some warm clothes.
In Dalabandin I explained I had no money and stayed at the police station, no questions asked.
We arrived in Quetta next day around 5.30 pm, too late to get a NOC. Turned bloomstar down and was brought to police station, which proved to be much more hospitable. Second day I pushed the police to bring me to home department early so that I could catch one of the morning trains out of Quetta. It proved useless as we ended up waiting for the head boss to check in at 11 am and approve my NOC. However the clerks were keen on giving me a NOC for travel by bus the same day and said there would be buses running later in the afternoon. Escort came to pick me up and we still tried our luck at the train station in case one of the trains was leaving late, but they had all gone.
We then went to the bus station and booked a ticket for the next bus at 6 pm. The ticket officer was reluctant to give the ticket because he said the many military checkpoints would take extra time to check me up and that would delay the bus. My police escort pushed him and I ended up getting a ticket for 700 rupees. Went back to another police station to wait for the bus, where the same police man helped me to order some food from outside. Went back at 5.30 to get on the bus. All was good but as the bus was about to leave the police came on the bus and asked me to come back. The police man asked for my ticket and went to the counter and came back to hand me 700 rupees. Either the bus company or the police freaked out last minute that I would be sent back to Quetta because night was coming (the NOC did state clearly that I was not allowed to travel after sunset and before sundown).
Went back to the police station where I was asked if I wanted to go to Bloomstar (it was a different station that the one I had stayed the night before). I told them it was too expensive and they let me stay at the police station where I was invited for dinner, tea and offered to sleep in a room.
Next morning my escort was super duper early and we waited at the train station one hour before the booking office opened. I was handed out to the railway police . I pushed them to bring me to the booking office before it opens so I would have my stand in queue and a chance to get a ticket out before they sold out. The officer preferred to take his time and then play it VIP at the ticket office. I was put on Akbar express to Sukkur and left at 10.30 am (400 rupees, economy). For updated info pakrail.gov.pk is very fine.
On the train I was asked for my passport and/or details at pretty much every stop, but it didnt delay the train or cause any trouble and the officers were always very pleasant, as pretty much everyone else in Pakistan for the exception of Bloomstar's manager (he's a rude punk).
Arrived in Sukkur and was picked up by my CS host and we rushed out in case police would ask any questions or mandate me to get security, but in the end I think our concern was unnecessary.