In early game (settlers, not engineers), it takes 3 days to build on a non-river grass/plain/desert. We are most assuredly going to use that grass-shield. We get a "free" work day by building now. Plus, it gives us time to examine the 2 tiles around the hut, which may well tell us if one of those grasslands are a (hidden) special. It other words, when we see the 2-square radius around teh hut, we will likely learn a great deal, unless it is all grassland or immediate coastline (thus blocking terrain examination to the north and east; unlikely, based on the graphic).
A 2-move unit (horsie) will be aboe to rapidly sweep to the northwest, to tell us of rivers and terrain that direction. Building the road gives us the time to explore enough to decide the best site, while still roading (roads are important for defense against Barbs & killing barb leaders for the 150g after turn 16).