Yes, you can walk over the Granville Street Bridge in Vancouver.
The walk, including bridge approaches is approximately 1 kilometer and offers views of downtown Vancouver, False Creek, and English Bay. Sidewalks on both sides are narrow, and may be shared with cyclists.
To reach Granville Island on foot, the best approach is to use the bridge’s east sidewalk, but use the crosswalk at the end to stay on Granville Street. Further along there will be steps on the left leading down to Granville Loop Park and from there walk back under the bridge towards Granville Island.