The Ann Arbor Transportation Authority's Route 7 is a direct route from downtown Ann Arbor to the Briarwood Mall, making the scheduled trip in 22 minutes and leaving the Blake Transit Center at 18 and 48 minutes after the hour. The return trip is scheduled to take 24 minutes and leaves on at 21 and 51 minutes after the house. Route 7 extends on as far west as Washtenaw Community College and St Joseph Mercy Hospital. This account describes some things I saw and can explain - or puzzle over - when I took the bus to Briarwood Monday afternoon.

For maps and schedules, see the Route 7: South Main - East pages in The Ride Guide or online. You can also ask questions on Facebook, call 734-996-0400 or visit www.TheRide.org for help.

There is a Downtown Development Authority parking lot, managed by Republic Parking, next to the Blake Transit Center at South Fifth Avenue and East William Street. The top surface of the pavement looks gravelly, I notice. I wonder what the specification was for this top surface, and how it differs from the Sylvan Avenue pavement that was just installed. And if that answer is not obvious from a search of the Internet, who would know who to ask?

The people in back of me on the bus are speaking German rapidly, in an accent that I can't quite place and can't quite understand. I do best with parents speaking German to their preschoolers.

Both of the Zipcars at the Palio lot are in use, and their spaces are empty. Where are all of the Zipcar parking spaces? They are listed on the getDowntown Zipcar information page.

The pavement at South Main Street and West William Street has a traffic sensor embedded in it, which looks to the rest of the world like a big metal square. I wonder how that works, what it's hooked up to, and how you could build one yourself to see if someone has parked in your parking place. This paper, Detection of Bicycles by Quadrupole Loops at Demand-Actuated Traffic Signals by Steven G. Goodridge, Ph. D., Member IEEE, gives the brief description of how it works:

"Inductive-loop traffic detector systems operate by sensing disturbances to the electromagnetic field over a coil of wire built into the roadway (Figure 1). When a conductive object (typically made of metal) enters the area over the wire loop, the magnetic field generated by alternating electrical current in the signal detector circuit induces weak electrical currents in the conductive object. (The AC frequency may be between 10,000 and 200,000 Hz, typically around 20,000 - 30,000 Hz.) The electrical currents induced in the object generate their own magnetic field that works in opposition to the magnetic field generated by the sensor coil (due to Lenz's Law). This opposition changes the resonant frequency of the sensor circuit by reducing the effective inductance of the sensor coil. This change in resonant frequency (an increase in frequency as the inductance decreases)  is detected by the circuit instrumentation in the signal controller cabinet, which then tells the signal control electronics that a vehicle is present."

There is quite a bit of graffiti on the Ann Arbor Railroad signal box at the signal on S Main St at the tracks. Two ordinances would appear to apply. The city graffiti ordinance requires the property owner to clean up the graffiti; and the state law regarding railroad trespass makes it illegal to put the graffiti on in the first place. City code 9:6:

(3) No person who owns or otherwise controls or manages any property shall permit or allow any graffiti to be or remain on any surface or structure on the property beyond the time indicated in a notice, which shall be no less than seven (7) calendar days after the notice is posted on the property or delivered to the property owner and no less than nine (9) calendar days if the notice is mailed. If removal of the graffiti by the date set in the notice is not possible due to weather or other reasonable cause, then on or before the date set in the notice the person to whom the notice is issued or his or her agent shall contact the City as indicated in the notice to request an extension. Removal of graffiti may be by means of actual physical removal or covering the graffiti over with paint or other similar substance applied to the surface or structure.

Gas at the Clark station at the corner of South Main and East Madison streets was $2.859 for regular. I try to check DetroitGasPrices.com for more prices and a map of prices across where I am likely to need gas. Heading north this weekend, gas was noticably cheap near Alma and St Johns.

Television antennas on the roofs of houses in Ann Arbor point east-northeast toward the towers located in Southfield. A few sites will help you pick up better HDTV signals by properly matching your antenna; I found AntennaWeb and an FCC Digital Reception Map.

A big sign for the TWall Foundation is up at All Star Driving, next to the Michigan Stadium.

A set of five video cameras look down on the northwest corner of Michigan Stadium onto the street; another set look from the southwest corner. Opening kickoff is coming sooner than you think.

Construction on the new stormwater retention system at Pioneer High School is done.

Valhalla Drive is a private road, due for major work to install new sewer and water systems. It's currently a township island:

"Washtenaw County regulations require that residential onsite water and sewage disposal systems be inspected at the time ownership of property is transferred. According to the Washtenaw County Environmental Health Division records, a portion of the septic tanks and drainage fields are not in compliance with current construction standards. The tanks and drain fields are undersized. Most of the drain fields were constructed of clay or concrete tile, which has a tendency to plug and prevent proper infiltration of the effluent. Installation of replacement septic tanks and drain fields may not comply with current isolations standards due to the density of the surrounding development and the lot sizes."

You can see the new University of Michigan soccer stadium from South Main Street. Can you get to it without crossing private property? The official address is 2250 S. State St.

South Main Street crosses Mallett's Creek between Oakbrook Drive and Harbor Way.

There is purple loosestrife (Lythrum salicaria) visible in the drainage channel along West Eisenhower Parkway on the north side. It's on the Plant Conservation Alliance's Least Wanted List for alien species.

My trip ended at Briarwood Mall, arriving about 20 minutes after I left downtown. A security guard zipped past on a Segway. There are comfy chairs near Sears, and the mall has wireless Internet.

Edward Vielmetti rides the bus for AnnArbor.com. Contact him at edwardvielmetti@annarbor.com.