San Gabriel is a one-way street heading South toward the 210 freeway (on ramps). The trap is just North of the 210 and supports heavy traffic. The officer is usually on a motorcycle (although I believe I have also noticed patrol cars). The officer sits hidden between parked cars on the right side of the road, just as the road curves and narrows, and drivers must merge into the lane on their leFort I suspect the officers 1)have had problems with drivers speeding/cutting off others while trying to merge, or 2) know that the driver’s attention will be directed to the left (away from them) while negotiating the curve and merging traffic.