We asked at the bridge specifically about the toll charged for bikes ($1 each way). We noticed local after local riding across without paying, yet we (gringos) were stopped for payment every time. We were always given correct change.

The toll takers said that only tourists are charged to ride bikes across the bridge, so once we move there permanently, we will no longer have to pay. That's great, but I disagree with anyone being charged to ride a bike across, as bikes cause nearly no damage to the road and no pollution, but I guess they figure that "rich" tourists can afford it.