If you're planning to travel from the Baltimore area to the beach this weekend, it would be wise to take a little time to calculate your Bay Bridge tipping point.
What's that, you wonder?
The Bay Bridge tipping point (BBTP) is the geographical point at which a driver would be better off heading north and going around the top of the bay than he or she would be using the Bay Bridge.
A little history: For decades, the only roads to Ocean City or the Delaware Shore were those that took the route via Elkton in Cecil County. It was a slow trip over many two-lane country roads. The only practical alternative was a ferry across the bay.
Then in 1952 came the Bay Bridge -- or what is now the two-lane eastbound span. Suddenly, hours were lopped off the trip to the ocean -- leading to booming growth in Ocean City and the Delaware resorts. The Bay Bridge quickly became the default route for everyone in the Baltimore area. Its primacy was reconfirmed in th 1970s when the three-lane westbound span opened.
But the equation has changed in recent years. Congestion on the Bay Bridge has grown, and traffic jams can add an hour or more to travel time at peak hours. Any kind of accident or incident can tie up the bridge for hours. Then you have another potential choke point at the Bay Bridge's Mini-Me at Kent Narrows.
Meanwhile the trip around the top of the bay has improved. U.S. 40 gave way to Interstate 95 in the 1960s, and the main routes through the Delmarva Peninsula have been widened and improved. Delaware completed its Route 1 as an interstate-quality toll road. Traveling to the Shore via Elkton has become viable again.
Each individual's BBTP is different based on starting point, ending point, time of travel and personal preferences. If you have a low tolerance for long backups, your tipping point may be farther south than a more laid-back individual's BBTP.
The first step is to calculate your raw BBTP. You can do this using Mapquest or Google Maps or any other mapping program that may be available.
First you need the address of your starting point and that of your beach destination. The tipping point can change depending on destination. If you're heading to Rehoboth, your BBTP will be far different than if you're heading to Ocean City. Whether you're headed to downtown O.C. or the north end of the barrier island can tip the decision of routes.
Then do a rough plotting of the course. If it takes you around the north of the bay, it's almost certain that will be the better route for you. That means your tipping point is to the south. Generally, the raw BBTP for central Ocean City is right around Putty Hill. Anywhere north of that, you should go north; anywhere south, use the Bay Bridge.
But the raw BBTP isn't the important one -- except if you're traveling at a time when you can expect the roads to be congestion free. What you need to know is the Adjusted BBTP.
To get that, you need to know approximately how long it will take to travel using both routes. Mapquest and Google both allow for override strategies that will let you calculate approximate time of traveling via each route. The difference between the two is crucial to calculating your BBTP.
Mapquest, for instance, estimates the time it will take to get from The Sun building at 501 N. Calvert St. to a hotel at 9100 Coastal Highway at 2 hours, 52 minutes. To go via the northern route would take you 3 hours, 16 minutes. But its default northern route takes you through tthe Delaware Toll Plaza, which must be avoided at all costs. (Besides being a rip-off, the Delaware Toll Road can back you up for an hour just so it can overcharge you.) A simple avoidance strategy, using Pulaski Highway and N. Mauldin Ave. in the town of North East as an interim destination, turns that into a 3 hour, 18 minute estimate. (There is a method to this madness. That's the exact point that will give you an accurate estimate on the best route to the beach. I've tested it.)
So now your difference is 26 minutes in favor of the Bay Bridge. Here's where science hands off the ball to art.
Now you need to use your experience, any information you can gather and a dollop of common sense to arrive at your Adjusted BBTP. Considering your time of departure, you need to estimate the level of congestion you would encounter on either route.
Let's say you're leaving at 4 p.m. on the Friday before a major beach holiday. You know you can anticipate some delay on Interstate 95 around White Marsh, but you also know it's a time of peak congestion on the Bay Bridge and its approaches. At such times the traffic on U.S. 50 can back up to Interstate 97 and lead to delays of 30 minutes to an hour.
So let's estimate backups will add 15 minutes to the trip up Interstate 95 and 45 minutes to get to and across the Bay Bridge. That 30-minute difference wipes out the Bay Bridge's advantage in the raw BBTP by 4 minutes and places The Sun building just north of the tipping point.
Now let's say you've called 1-877-BAYSPAN or signed on to baybridge.com and determined that high winds have prevented two-way operations on the bridge. You're looking at a full-blown mess on the bridge, with all that beach-bound traffic confined to two lanes. The delay could be an hour or more. The adjusted tipping point could go as south as Ellicott City or Glen Burnie. (For Annapolis and Washington, it would probably take a catastrophic crash to bring the tipping point into play.)
You can further adjust the BBTP to reflect your own tolerance level for backups. If you can sit out an hour's backup without batting an eye, leave the adjusted BBTP where it is. If sitting in traffic drives your blood pressure up to dangerous levels, add extra minutes to your Bay Bridge congestion assumption.
There are no guarantees this approach will work on every trip. Sometimes traffic flows freely across the Bay Bridge at the most busy times; a traffic crash could always turn I-95 into a parking lot. Delaware Route 1 can back up at toll plaza. (Using U.S. 13 as far as Delaware Route 42, then cutting over to 1 to avoid Dover, might be a smart move.)
Much of Baltimore and Baltimore County lie very close to the tipping point for Ocean City at peak times. Rehoboth Beach can be on the edge at other times. My suggestion is that close calls be resolved in favor of the northern route. The tolls are higher, but the chances of a really bad trip are far less. If I-95 gets jammed you can bail out and use U.S. 40 or Maryland Route 7. If the Bay Bridge is frozen, you're out of luck.
P.S. I am skeptical about Mapquest's notion of going to Fenwick Island, Del., or north Ocean City using the coastal Delaware 1 during times of heavy travel. I would stay on U.S. 113 and then use less-traveled Delaware Route 20 to Route 54 and connect with Fenwick at Delaware 1. And if you go the Bay Bridge route, resist Mapquest's effort to send you on Maryland Route 2, instead of Interstate 97, unless it's the dead of night or you're starting from Glen Burnie or Severna Park.
As always, the smart driver travels with a good map. You can trust it when GPS, Mapquest and Google let you down.
(Photo by Kenneth K. Lam/Baltimore Sun)