score:1
There is no rule whatsoever preventing you from entering by means of hitchhiking.
In general, foreigners from low-risk non-Russian speaking countries aren't questioned at all; the FSB simply checks that the passport and visa is in order and then stamps you in.
Upvote:2
I can't guarantee that there will be no problems but I don't believe there would.
It's a busy checkpoint since the bulk of traffic between Latvia and Russia goes through it, and they are accustomized to all kinds of strangers there: the Baltics are known for low cost flights and Russia isn't, hence the traffic.