Air carrier Captain reported having to stop the aircraft due to a ground vehicle crossing in front of the aircraft during taxi to the gate. Flight continued to the gate.

Narrative

We taxied in single engine for Gate XX; entering the ramp at spot XX.Approaching the gate; we would have a sharp; tight turn to the right into our gate of over 110º (roughly; far beyond a 90º turn). I stopped the aircraft well short of my turn point as there was equipment still parked in the gate (trucks and bag carts) and wanted to be able to see the entire gate from the left seat to ensure it was clear; and observed ramp control that it might be a minute.Once the service equipment was clear; I began taxing forward; bringing the nose past the centerline in order to swing into the gate. Just as I was about to make my turn; a ground vehicle crossed the stop line and blocked my access from the left. I stopped the aircraft and waited for them to proceed. At this point; another vehicle remained stationary; but past point where I felt my nose would come during the turn into the gate.My first officer attempted to signal them to move forward; to no avail. Furthermore; we no longer had visual confirmation that the right side of the gate area was clear to begin our turn in as it was well behind the wing and not visible from our vantage point. We were also now blocking the spot XY taxi lane into the alley as well. I advised ramp control we would remain stationary; and required wing walkers to direct/stop traffic before we would proceed into the gate; as we could no longer ensure it was and would remain clear of hazards.Cause: The lack of wing walkers to spot hazards not visible to us; and direct traffic created a significant safety hazard for all involved. I can't really fault the driver who didn't yield; as from his perspective I'm sure it looked like I was proceeding past that gate; and would have been surprised to see me begin the turn in. Thankfully they did that from the left where I could see them; had this happened from the right side; I never would have seen them; and could very well have swung the nose right into someone shooting that gap.Furthermore; while we were able to proceed safely with just wing walkers; in retrospect; the lack of a masharller relaying signals from the right side wing walker who was not readily visible was another hazard to the aircraft and those on the ground.