Numbers are spinning inside the Intrepid Commuter's head like a baseball fan perusing the morning's box scores.
What's the busiest stretch of interstate in the Baltimore area? That would be the Beltway between Interstate 83 north and I-83 south in Baltimore County.
The least traffic-burdened stretch of Maryland highway? Must be the road to Hooper's Island in Dorchester County, which only gets 200 vehicles each day.
Did you know the Key Bridge handles half as many cars and trucks as the Harbor Tunnel and fewer than a third the number handled by the Fort McHenry Tunnel?
How about this for curious: Route 29 in Howard County has to bear as much traffic as the Baltimore-Washington Parkway, and U.S. 1 in Harford County is busier than Interstate 97 in Anne Arundel County.
The source of all this trivia is a 3-by-5-foot map published annually by the State Highway Administration.
Don't plan to buy one if you're lost. The map doesn't show any side streets, just state-maintained roads. It's not even very interesting to look at, just black and white (no scenic highways noted; no guides to the best motels or eateries).
But if you're in the traffic planning business, the information contained in the "Traffic Volume Map 1992" is invaluable.
The map draws its numbers from the state's network of traffic sensors. Some are buried in the pavement and detect passing cars and trucks by the disturbance they create in a magnetic field.
Others consist of rubber tubes temporarily stretched across roads. Tires passing across them trip an air switch.
In either case, the sensors determine how many vehicles are traveling on a given stretch of road each day. The results are compiled in map form, which is the most convenient way of looking at the data.
"It allows us to look at trends and characteristics of traffic at a glance," says Ronald D. Lipps, the SHA's traffic safety chief.
Studying the information, planners can figure whether a given road needs to be widened or a traffic light should be added to a busy intersection. They can calculate pavement wear and plot when a road will need to be resurfaced.
Entrepreneurs also find it useful. Want to open a fast-food franchise? Better check out the number of cars that pass by that spot each day.
You can credit the traffic counts for the state's recent decision to upgrade the intersection of Harford Road (Route 147) and Route 152 near the Harford County community of Fallston.
It's a typical example of how the SHA reacts to traffic volume. Harford Road has been experiencing a growing number of commuters -- 20,000 vehicles per day compared to 15,000 in 1986 -- a one-third increase.
Traffic planners project the volume will increase another 25 percent in a decade.
Brian Dolan, the SHA's assistant district engineer for construc
tion in Baltimore and Harford counties, says that estimate was a key reason the SHA decided to add left turn lanes on both directions of Harford Road.
"There's more than sheer volumes involved, but it's one of the first things you look at," Mr. Dolan says.
Planners also looked at accident statistics, signal timing, even videotapes of traffic movement before reaching the decision to upgrade the intersection, he says. The $307,500 project is expected to be completed by late fall.
Traffic volume maps of the state can be ordered for $3 (including postage and handling) from the SHA by calling 321-3520. More detailed county maps also can be purchased for $5 each.
Homeland to buses: Hit the road, Jack
Baltimore resident Jane White rides the bus to work and she's unhappy with neighbors who want to ride the Mass Transit Administration straight out of Homeland.
The problem, she says, is that a small but vocal group of people don't like the noise caused by the No. 11. They have managed to persuade the Homeland Association to ask the MTA to reroute the buses to nearby Charles Street.
She says the action is shortsighted, particularly when new state regulations are going to require employers to get more of their workers to ride buses to the job.
"The vociferous complaints about noise disturbance by a few new residents on the bus-route streets have carried the day," she laments.
Andrew J. A. Chriss, the association's president, confirms that his board has voted to ask the MTA to reroute one-third of weekday buses, one-half of Saturday buses and all the buses on Sundays and holidays.
Currently, 35 buses travel along Saint Albans Way and Springlake Way on weekdays. People who live on those residential streets complain not just about noise, he says, but about the unpleasant exhaust fumes and the danger posed by the buses.
"We value bus service; it's the reason many people decided to live in this neighborhood. But people's homes are being rocked by these things," Mr. Chriss says.
He believes the association's request to the MTA is a compromise. Some people wanted all the buses rerouted.
KEEP IN TOUCH
Write to the Intrepid Commuter, c/o The Baltimore Sun, P.O. Box 1377, Baltimore 21278. Please include your name and telephone number so we can reach you if we have any questions.
Or use your Touch-Tone phone to call Sundial, The Baltimore Sun's telephone information service, at 783-1800, and enter Ext. 4305. Call 268-7736 in Anne Arundel County.