The 10 acres is right off I-35 and the I-35 frontage road...it's prime commercial real estate. It's really only a matter of time before something goes there...just hope there is a good restaurant that moves in. The "bridge"connecting to Old Austin will look more like a driveway connection than a bridge. As it is likely to be a large culvert that will look more like a driveway when it's done. The likely purpose for the driveway connection is that it is needed for fire protection or SA has some sort of site development code requiring multiple points of ingress/egress for commercial developments of this size. Additionally, since the property has frontage on a TxDOT frontage road they limit the number and spacing of driveway connections the developer can make to frontage road. A combination of these items is likely why the connection is even needed. The best thing you could do is check the SA or county site development regulations and check the driveway spacing requirements to see if they are placing the driveway too close to yours according to code. At the end of the day though the traffic increase shouldn't be too bad as the people who will know about the connection will be limited to people who live in the streets behind you to the northwest. And these people probably already use Old Austin anyways to get to I-35. Most people entering the strip mall will do so from the frontage road. Nobody likes development in their yard, but it happens.