Google cheats here, though. They were able to show a recently completed bridge as completed simply by the fact that traffic was passing over it. OSM still had it within half an hour of opening, though.
The other way around is where OpenStreetMap is faster though. With Google a road which is closed (or gone) for a longer while means someone has to report it and Google employees verify it. Doing this automatically based on traffic dropping to zero is not really possible, because the algorithm doesn't know why traffic is rerouted or for how long. This can take a while depending on the number of people reporting it to Google. OpenStreetMap mappers can act autonomously much faster (errors are sometimes made, but often picked up and reverted just as fast for high profile stuff).
Google actually fucks up royally when a road below the level of a motorway/freeway is closed and formally withdrawn from public use, but still sees some traffic (by people illegally using it and people with legitimate goals like construction workers). There is a road near me where this is the case. Google will happily route cars over a road where one of the two lanes is in use as a soil depot for the nearby housing developments, and gates on both sides block the road. Those gates are shoved aside or bypassed by driving through the grass by a handful of simpletons. A bit of observation during a walk there showed me two cars passing there illegally; a postal worker and a power utility guy. Two types of road users who likely use Google Maps quite a lot, and drive up the virtual traffic there.
On OpenStreetMap this road is simply closed and limited to private use (i.e., the construction workers hauling soil), and has been for a number of years now.
Google took about 6 months to accept my edit to an incorrectly named park near me. I took pictures of the signs as proof of course I could not submit them as evidence but a thought someone else would report it. In OSM I could change it in a few minutes and I am not very familiar with the tool.
I personally know someone with a similar story (small pedestrian path that existed in real life but missing from Google maps). He made the effort to flag it, provide proof etc etc.
What I told him was you guys be nuts to be spending your time to improve Google's product.
Google has the private road of a local landfill labelled as a bike path. They label little paths in cemeteries as bike paths. Its a little embarrassing how much they rely on automatic data vs, you know, a cities own published bike network maps.
