I think that a complete lockdown is a possibility, but it depends a lot on how things progress over the next week or two. We’re already, to varying degrees, on partial lockdown and my employer (electric utility) is planning sequestering of key people if necessary.
2 weeks would likely be the time frame, possibly even 3 IMHO, to cover for errors in estimating the time frame of the virus itself.
If the “voluntary” stuff works, then we won’t see that, but it makes sense to have that plan available as a last resort.
Coronavirus In Chicago: Midway Traffic Control Tower Closing After 3 Workers Test Positive For COVID-19
this can’t be a good sign...