To reach the actual Research site, you have to make a long jump from the ramp in the highway to the small island. Even if you fall short, as long as you’re near the shore, just you can still push your Bike to that island.
From that island, you have to make another jump to reach the shore on the other side of the river. Continue around to find the Crash site and the hard case with the Injector. There’s also a renegade cairn nearby so kick that as well.
To get back to the highway, back off a bit (to gain more momentum) then jump off the ramp shown below.