It shows routes taken on layer 3 of OSI model (the network, not just router info). So, it shows path taken using packets sent and received. Path is shown as ip address and/or host names.
So, to continue your road analogy, using tracert to identify problems is one thing, but to fix these issues would be the equivalent of having to call the various Departments of transportation to ask them to fix road closures mapped out on a thousand mile vacation you have planned?
I suppose that's true; mainly because you are limited to tools you have. Unless, you work as part of network support team or happen to be the system admin/network admin for the segment that has gone bad. Which could be that one guy out of 100+ simply because the org you work for might be huge. I work for Verizon and that's pretty much what happens. You find and issue, report the issue, 100 different people are contacted, and then at some point they reach who ever has the access (physical or other wise). This could be a bad server, switch, trunk or etc... anywhere in US or INTL.
