There are ramps to/from the bridge over the freeway.
Ramp up to bridge:
The rotating gate might seem like an obstacle, but I believe it is quite large/wide. There are a lot of people who pass through these with large parcels, crates, trolleys, luggage, strollers, etc. I imagine a wheelchair should be fine but I haven’t seen anyone pass through with these.
Here is a screenshot from Google Street View showing the gate. That could be another gate to the left of the fence, but it doesn’t look like that actually has access from the ramp.