Increasing numbers of areas in OSM are starting to become "complete" or at least have a good coverage of the basic features. With this, the focus in OSM imho should increasingly move more towards "maintanance mode", ensuring that our data remains at the level of quality and up-to-dateness we pride our selves with.
So far, the majority use of OSM has probably been in webmaps and bitmap tiles, as it is a rather forgiving application with respect to data quality. Other areas that OSM is starting to push into, particularly routing, are less so. One particular aspect that is obviously very important for routing (and other applications), is connectivity or network topology. I.e. saying if one way is connected to another and if it is therefore possible to travel between them.
Unfortunately OSM seems to have a bit of a problem with connectivity and a surprisingly large number of roads and footways are drawn to end close by, but don't share a common node, i.e. meaning they are not connected. Luckily someone (was it Pascal Neis?) has made a great tool available through Geofabrik's OSM Inspektor to highlight all the roads and paths that end close (less than 1-5 meters) to another road or path, but aren't connected.
As you can see from the screen shot above, there are many of these nearly connected ways that need fixing! So let's all try and get those nearly connected ways connected and remove those red dots from the map! Head over to the OSM-Inspektor routing view and start fixing! The routing view is now available for all of Europe after only being created for Germany in the past.
Keepright, another great QA tool, between, has a similar check with its "Almost-junctions" check, and indeed several more really useful checks! So another good opportunity to fix those bugs.
As always, with any automated quality assurance tool, there will occasionally be false positives, where the way truly does reach very close but is not connected, as there might be a wall, fence or a 1000m drop preventing you to get from one way to the other. So please be careful and let the usual commen sense prevail when fixing these issues.