Chris made this for me a number of years ago... (2010? Earlier?) A prized part of my collection!
Sakbe Roads are a key feature of Tekumel. They are huge highways, a combination of Roman Road and Great Wall, that crisscross the great Empires.
There are 3 tiers: the lowest and widest being for commoners, marching legions, etc; the second level is for officials, nobles, temple traffic (the toffs!); the third and narrowest level is restricted to road guards and Imperial Messengers. The upper most level is the side that faces the nearest frontier. There are sakbe road towers at frequent intervals and also large citadels and legion fortresses. This is a smaller version. Chris also made a caravanserai platform that is commonly found adjacent to the on ramps.
More pics, including interior shots - yes, the tower comes apart - can be found here:
https://www.pinterest.ca/howardfielding7/follow-the-s%C3%A1kbe-road/NOTE: I just realized that these are not pics of the finished product! Well, the first one might be, but there are doors fitted, so the others are actually "in progress" shots Chris sent me, way back when. Also, the link above shows some construction pics. Hope I'm not giving away your secrets, Chris?!