yeah I'm a little confused because practically all crosswalks in Chicago no longer have beg buttons. Maybe this wasn't true in 2015. This might be one across Lake Shore Drive, at Monroe perhaps (https://www.google.com/maps/@41.8810438,-87.6172572,3a,75y,2...)? That does have a beg button but despite living a few blocks from there, I'm not sure if it does anything or not...