The date of the inspection trip is "Fall 1926" and the location is "Mitchell Boulevard." Look closely at the background. There are two tracks. These diverge to the right on the west side of Mitchell Boulevard and climb to Wells Street. (The curved retaining wall north of the expressway dates to this construction.) The inspection trip is on the recently-built eastbound track of the Rapid Transit Line. There is room for the westbound track, and both tracks will subsequently be extended to connect to two new tracks to the south of the streetcar tracks in the open space at left. The odd-shaped high-tension towers in this part of town were designed to support the overhead wire for four tracks. There are still a few New Havenish low towers supporting some of the low-tension lines that also date to this installation.
That "Fall 1926" date intrigues. The information I have gives the opening of the Rapid Transit Line from Soldiers Home to Park Hill Avenue as 4 June 1926. The section from 68th Street to Soldiers Home was completed on 20 June 1928. That section is clearly not yet begun.
I have my doubts, however, about that inspection trip date. It's unlikely that The Milwaukee Electric would be running its local Rapid Transit service on a long stretch of single track so close to the city limits.
The photographer is standing in what is now the berm between the expressway and one of the north overflow parking lots for Miller Park. A train like this, perhaps one with a parlor car and a cooler full of Miller or Pabst, would make the experience so much better.