The link you provided goes to the main CityStrides site so we can’t see the activity you are referring to. An activity link should look like CityStrides. You’ll also want to make sure the activity is set to public or else even if you provide the link, we won’t be able to access it.
Nodes are checked off if your activity’s GPS reports coordinates within 25 meters of a node. So unless this is a really wide street, you may also have an issue with GPS wobble. It’s a common issue in cities with large buildings, could happen in bad weather or variety of other reasons. You could try using a GPS editor to edit your activity’s GPX file and then re-upload but that can be a pain as it can sometimes require editing hundreds of nodes.
If as you say it’s a dangerous segment, take the easy route and mark it off manually (see ‘Capturing Inaccessible Nodes’ at bottom). Tl;dr - If you’ve run every segment of road you feel comfortable running yet there are a couple nodes you don’t feel safe getting, go to the street’s page and select the Mark as manually complete button.