What's the opposite of "further down" in "further down the road"?

Solution 1:

If James and the speaker are both heading in the same direction, then Matthew is further back down the road (or simply further back, or back down the road [behind the speaker]) with respect to both of them.

Even if James was coming towards the approaching speaker, he would understand further back as relating to the speaker, not to himself.

How could it be otherwise? After all, the speaker has not yet been on the stretch of road that lies behind James, so he could have no way yet of knowing what other person might be there. Common sense therefore tells James that the speaker can only be talking about someone he (the speaker) has passed along the stretch of road that lies in the opposite direction to the one that James is coming from.

This question is not as complicated to answer as the discussions here suggest. All the participants in this scenario have a front and a back, and they know what direction of movement means. The ability to relate external phenomena to oneself, to one's own anatomy and its orientation, and also to other people's point of view, is a fundamental cognitive ability that all normal humans employ both conceptually and in their metaphorical use of language.

Using this starting point, James and the speaker can intuit everything that is relevant to their relative positions and how best to refer to them.

Solution 2:

Further up would be the intuitive opposite of further down.

Further does not indicate direction, but rather distance.

At, to, or by a greater distance

(used to indicate the extent to which one thing or person is or becomes distant from another):

You could say "higher up the road", but "higher" might imply the road was climbing in altitude. In the conversations you mentioned, it would be fine to say "further up the road". In both phrases "further" indicates distance, and since "up" is the opposite of "down", "further up the road" would be closer to the opposite of "further down the road".

One thing to remember is that Matthew, the first person you talked to, set an arbitrary frame of reference by referring to one direction as "down". His rationale for that frame of reference could be:

• South rather than North
• Descending rather than ascending
• Backward rather than forward (with respect to you OR him)
• Toward town rather than away from town (or vice versa in some locations)

There's a good chance Matthew hasn't even consciously chosen that reference.

You can not guarantee that James, the second person you talk to, shares Matthew's internal frame of reference. For the sake of communication, you would want to find a way to compare Matthew's frame of reference to James's frame of reference. Unless James is blind, you could simply point toward the place you left Matthew, while saying, "I saw Matthew further up the road." That gives James the opportunity to test your subjective use of the word "up" with objective data.

The other communication problem, and I consider it less critical, is that further functions as a comparative adverb. Matthew is comparing James's distance to what? Again, you have no way of knowing that James's spacial comparison will match Matthew's. The good news is that the human mind is perfectly capable of holding that kind of ambiguity at bay in a situation like this. Unless James is a contrary buffoon, he'll go further up the road and find Matthew.

Solution 3:

In an objective description to a neutral audience, I would describe Matthew as "less far down the road than James," which conveys a situation interchangeable with the given, James is "further down the road" than Matthew.
In the specific example given, however, since neither the direction James is headed nor Matthew's direction are indicated, the speaker should tell James simply: "I saw Matthew back down the road."(This assumes that James sees which direction the speaker has come from.) The speaker wishes to convey to James that: Matthew is less distance down the road in the direction James sees the speaker going (it is not indicated which direction James is going in). Regardless of which direction James is going, he would then know where in the road Matthew is, because James is at the same place as the speaker at the time of encounter. Adding the word "further" to back would only be redundant, because at the point of speaking, the speaker is at an equal place as James, James knows where the speaker has come from, and back conveys Matthew's place in one word.