Around 3pm I believe.

I went through mid-morning and it was absolutely empty. Given the extreme differences in experiences depending on time of day, maybe the layout is ill-suited to higher pax volume.

shoes off

only difference

and probably more random searches/naked body scans for tsa beancounters or something

making sense of YYZ transborer area
 

I observed this mess @ YYZ last week. Fortunately, I have NEXUS and carry on only i.e. I was there for less than a minute. Here is what I know:
- the transborder security lines have been moved & there are big line-ups;
- after security, you need to self-scan your bp and wait in a holding area till your checked luggage is identified and you are called to confirm same;
- the next stop is US pre-clearance - which is now located in a massive hall where the old security lines and baggage belts were. Walk on through;
- At the transborder MLL, I asked the dragon why the security was moved? The answer (I am not kidding) is because the US Customs & Immigration pre-clearance agents did not want to be located in the same area as checked luggage. I am not kidding.

Any signs of the priority security yet ( http://www.aircanada.com/en/travelin.../security.html )?

// Edit: on more detailed reading, they don't offer gold track, and only rely on gold track in foreign airports...

In light of the attacks in Istanbul, maybe that's not so crazy. The vulnerability of the US customs hall can be reduced by eliminating the presence of unscanned checked luggage.

IIRC CBP agents were demanding to be armed due to the fact that passengers could legally have guns/knives/etc... when they arrived at the agents. This is in keeping with how they are armed at sea/land border crossings. The work around (because no country wants armed CBP agent on their territory), is to place all CBP agents behind security and provide an active, armed police presence in the area. Ergo, no one armed can get to CBP without effectively charging in, and even then would have get by the police, and therefore the agents don't have to be armed.

You'll see this change rolled out to all CBP pre-clearance facilities in the near future, and all new facilities require it as standard.

Do domestic connecting passengers still have to go through security? It doesn't make sense if we are screened by CATSA in Canada and still have to be screened again in Toronto if we didn't leave the secure area. Yes there are 'different standards', but I have been asked to take off my shoes on a domestic flight from YUL...

Yes you have to go through security screening as a domestic connecting passenger. Security is setup right before you enter a holding area before queuing up for the CBP formalities.

Just went through yesterday and the lines were longer for connecting passengers after this new procedure was implemented. (I have never flown a direct transborder flight from YYZ) Why can't OSS be implemented?!

I would imagine OSS for Int'l->US might never happen because of US requirements, although I don't have any hard evidence either way.

I also heard that the lines were being bogged down by travellers with big suitcases, whereas now travellers can move a bit faster through the line.

I interpreted Antonio8069's point about checked luggage as a security concern for CBP officers, not an efficiency one. Although I guess most of us wouldn't necessarily mind an improvement in efficiency... If only that's what we have here :D

But now passengers connecting from a domestic flight are sent through an area where there are only 2 security lanes. In the past when security was post-US customs, I remember there being 4-6 working security lanes. So connecting passengers do have to wait longer...

Honestly, just stop and have a coffee (to ensure enough time for your bag to transfer), reprint your BP at a kiosk to it doesn't show as being printed elsewhere and go through the front. Now that everyone drops bags before hand, all CBP kiosks are setup at scan the BPs and see the bags.