Seismic Retrofitting Project closes a sidewalk of the Golden Gate Bridge SAN FRANCISCO (KGO) Cyclists and pedestrians now have to share the eastern sidewalk of the Golden Gate Bridge after crews closed the western one Monday morning, for a long-term seismic retrofitting project. The Golden Gate Bridge just got smaller today. Smaller for the tourists and others who walk across this majestic span on the east sidewalk and smaller for cyclists who must now join those hoofers at all times while the west side undergoes a seismic upgrade. Not many people on the bridge on this wet and windy day, but still the two groups were having issues. Christian Vollenhefer from Austria had to zig and zag during his jog.   "It was a little bit difficult down there on the other side because we had not seen them coming from behind and they nearly crashed into us," said Vollenhefer. But earlier this morning, a bicyclist said it was the pedestrians who are not paying attention.   "They don't really pay attention to us. You see a lot of people just blocking the whole way. Just enjoying the walk out here," said Sausalito resident Alex Quiroga. This weekend and for the next four months of the tourist season, the sidewalk sharing will be put to the test. On the busiest days, 10,000 walkers and 6,000 bicyclists are on the bridge. In the next few weeks, bridge officials will consider a plan to put a stripe down the middle of the east sidewalk, one side for pedestrians the other for riders.   Bruce Schreiber of Florida thinks that might help clarify the right of way.   "I'm afraid that when it is busy, people don't know what side of the walkway to go on, and I don't know what the right of way is, but I guess the fastest man rules," said Schreiber.   And bridge officials are still considering a speed limit for bicyclists. Whether common sense prevails or not, walking tourists are going to be closer to the railing while bikers and runners will be next to the 1ST vehicle traffic lane.   Maybe when bicyclists and/or runners have head-on collisions with each other, their injuries will make them walk the rest of the way to the end of the bridge. Work on the west side of the bridge will be going on for about four months.   After the west side reopens, then work will begin on the east side.