Thursday, July 18, 2013

Sagamore Bridge traffic can be a nightmare

After maddening events such as the gridlock created on Mother’s Day in 2012 or the 25-mile July 4th weekend backup this year, every amateur traffic engineer (including myself) gets to work at solving the problem of the Sagamore Bridge.


The Sagamore and Bourne Bridges were completed in 1935, a time before the Cape Cod summer bustle was as extreme as it has since become. The lane width on these bridges is ten feet, a full two feet skinnier than the standard widths used for bridge design today. Anything that further restricts the actual or perceived width of these lanes will, no doubt, slow down traffic even more.

In general, drivers are uncomfortable with the tight fit, especially in light of the high curb/sidewalk on one side and a high curb on the other. This is the primary reason why cars slow down when crossing the bridges and, ultimately, the constraint that leads to long backups at peak traffic times. Each bridge can manage just above 3,000 cars an hour. If 20,000 cars are leaving Cape Cod via the Sagamore Bridge between noon and 5:00pm on a Sunday, there will be a backup.

A menagerie of solutions for the Sagamore Bridge problem

Three lanes off/one lane on
This idea seems appealing at first blush and has been proposed as a Friday afternoon solution as well (three lanes on/one lane off). The problems with either of these proposals are:

1) Going back to the item noted above regarding anything that further narrows the lanes will slow down cars even more, the use of barrels, stanchions, pop-up dividers, or any other device to demarcate the three lanes in one direction from the one in the other would take up precious lane width, both actual and perceived. Furthermore, the double yellow line in the center of the bridge is in constant use. (How many times have you seen a car or truck with a tire on that centerline?) That is a clear indicator that the dividers would be mowed down in short order.

2) There are two-lane highways on either side of the bridge. Opening up the roadway to three lanes on the bridge would invite even bolder lane changes than we see now when drivers jockey to use one of the two exits on the north side of the Sagamore. Perhaps the left lane could be for Route 3 traffic only, one might suggest. A restriction such as this would require an additional series of barrels, stanchions, etc., between the two left lanes of the three lanes off, leaving the lane widths at nine feet or less.

Close down the entrance in front of the Christmas Tree Shop
There is support for this action because it is instinctive that this merging of traffic is jamming everything up. If this was the real constraint, then everyone would be flooring it immediately after passing this entrance and sailing across the bridge. The reality, on the other hand, is that traffic continues to crawl over the bridge, unclogging on the mainland side.

We could agree to disagree, but there is a way to determine whether it’s the bridge or the Christmas Tree Shop entrance that is the actual constraint. The bridge traffic counts are monitored 24/7 in both directions. By comparing the rate of flow at known peak times (that is, when there is a backup), one could determine if the southbound flow at peak is significantly higher than the northbound flow at peak. If that turns out to be the case, then the Christmas Tree Shop entrance would rise to the top of our culprits list. I will be requesting this comparison from the Department of Transportation to see what it reveals.

If the Exit 1 entrance does turn out to be a problem, closing it off is not going to be a panacea. One would assume that the options for a driver confronting this closure would be to continue on Route 6 to the Bourne Bridge or to circle back and join the fun at Exit 2. Our public safety officials in Bourne and Sandwich agree that both towns would be subject to frequent gridlock if this approach was taken. The three-mile stretch between the bridges on the two-lane Sandwich Road would also fill up quickly and block the residents living off of that road.

A better solution would be to reroute access from Route 6A by developing a one-way connector that runs along what is called Bayview Road which would start at the Sandwich/Bourne town line and dump into Route 6 about six-tenths of a mile south of Exit 1. This would relieve the jam up at the bridge while traffic could still use Exit 1 to leave Route 6.

Make each of the bridges one-way in opposite directions during peak times
That’s not going to happen.

Paint “fog lines” on the bridges
Fog lines are those white lines painted near the shoulder of a road to help drivers maintain their position within lanes on foggy nights. The theory here is that the narrow lanes and tall curbing on the bridges makes for nervous Nellies, which could be relieved by painting bright white lines next to the curbs to delineate the space a driver actually has at his/her disposal. A variation on this idea is to paint the sides of the curbing in a contrasting color to the pavement, accomplishing the same goal.

I find this intriguing in that there might be competing results from such a change. While better defining where the outside lane meets the curb, it might also create the perception of a narrower lane. As precarious as driving next to a tall curb may seem, relatively few people ever bump into it. Most of the scratches and gouges are courtesy of plow drivers, who apparently lose track of where their blades are in driving snow storms.

Move the sidewalk to the outside of the bridge
This seems like a no brainer, and like most no brainers, there’s more to the story. Although hanging a sidewalk on the outside of the bridge is doable, there is no road deck support under the existing sidewalk. In fact, the sidewalk is hollow, a space that is used for all of the utility cabling that crosses the Cape Cod Canal. To add an extra foot of width to each lane, which would still be substandard to the 12-foot widths that are used for new bridge construction, the infrastructure improvements would be very costly. It’s still worth consideration, however.

Add variable tolling (aka value pricing) to reduce traffic at peak times
“Avoid the rush, pay half as much.” This was the slogan for the Midpoint and Cape Coral Bridges in Lee County, Florida, when variable tolling was introduced in 1998. The discounted periods occurred before and after the normal morning and evening rushes on weekdays with driver paying half of the normal $1 toll. Today, the toll is $2 and the discount remains at 50 cents. “Avoid the rush, pay three-quarters as much” doesn’t have the same ring to it.

Of course, the bigger issue here is that there are no tolls. Adding an incentive to a current toll structure is certainly easier than selling the idea of tolling in the first place. The complication of the bridges being the property of the U.S. Government, operated by the Army Corps of Engineers, is an interesting one as well, though probably not unique.

Another problem is rooted in what economists call elasticity. It simply refers to how changing one variable affects others. In this case, if there is variable tolling, say $3 to cross at peak times and $1 to cross at nonpeak times (or even $3 at peak and zero at nonpeak), how effective would that be in encouraging people to avoid Friday or Sunday afternoons or noontime on Saturdays? Would a typical tourist care about $3 when it’s less than half of what he paid for a glass of wine the night before? There would be a point at which behaviors would change, no doubt, but that might be the same point at which a tourist decides that coming to the Cape is just not worth it.

Build a new bridge
As a permanent solution for our traffic woes, $320 million or so would pay for a new bridge to supplement the two existing bridges. Eliminating the Bourne and Sagamore Bridges altogether would cost more on the order of $600 million.

One proposal is to build a third bridge about halfway between the two existing bridges, funneling people from both Routes 3 and 25 across the canal with the option of heading towards Hyannis or Falmouth. Using land on the Massachusetts Military Reservation, soon to be Joint Base Cape Cod, feeder roads would connect traffic to/from Route 6 before Exit 2 and to/from Route 28 close to the Otis Rotary.

It is estimated that this new bridge would syphon off about 50% of the current traffic, turning the Bourne and Sagamore into “neighborhood” bridges. Another benefit would be that most heavy truck traffic would access the new bridge in order to avoid the Bourne Rotary and the tie-ups at Exit 1 on Route 6.

So what’s holding up the program? Setting aside all of the environmental issues, permitting, access to the MMR, etc., this would be mostly federally funded, which would put it up against many other Army Corps of Engineers projects across the country. To get on the list of accepted projects, there must be a “bang for the buck” that outstrips competing proposals.

The problem here is that 25-mile-long backups are a rare occurrence. Even the more typical six or eight mile backups only occur on summer Sundays and holiday Mondays and are usually dissipated within four or five hours. It would be a tough sell to propose infrastructure improvements sufficient to cover extreme peak usage when that usage is expected to occur only 10 or 15 times a year for durations of less than six hours. That’s about 90 to 100 hours out of nearly 8,800 a year, about one percent of the time.

Having worked in New York City, I could imagine a more compelling case for $320 million to be spent on traffic mitigation where the bridges are jammed up 16 hours a day, seven days a week.

Weigh in

I have received many excellent suggestions via my blog and email replies in the past. Now’s the time for you to weigh in with your ideas.


  1. I realize that there will be traffic backups at peak hours no matter what "solution" is put into place, yet it still baffles me that with the flyover there are still backups for over 6 miles. I think the main problem is the drivers themselves. People panic when they see the signs at the 2 mile mark for appropriate lanes for upcoming exits, drivers in the "passing" lane drive slower that the speed limit without a care in the world. Thus causing cars to pass on the right which is a problem in and of itself. At the x-mas tree on ramp, people don't utilize the every other car merge system ( which I feel helps keep the flow moving). These issues are not just during the peak hours with the bridges, but on all roads, all the time. With all the latest technology, GPS apps are everywhere, people should be able to manage getting from here to there. Maybe re-educating drivers on basic driving procedures, i.e. using blinkers, how to navigate a rotary - round about, passing lane vs. travel lane etc. might make a little difference. I find our Cape drivers to utilize this knowledge much more often than our visitors. I honestly don't think anything put into place will work until the drivers start paying attention. just a thought :)

  2. Hi Randy,

    Thank you for taking up this topic. While I don’t believe there are any quick fixes. You gave a thorough explanation of the options presented. I believe the main issue lies with the Sagamore and Bourne Bridges. As you described them, they are substandard in design. The Cape Cod Times published that they were evaluated as structurally deficient. The cost and time it takes to upkeep these bridges grow with each passing year. These bridges are also our primary evacuation route for any natural disasters, or if ever there was a concern with the Pilgrim Nuclear Plant. This is a public safety issue. Is this criteria being used by those who think they we only have a few backups each year? These bridges are not only for the convenience of Cape Cod residents or tourists, but are vital to the entire Cape economy. We all know how long it takes to get things done, especially with the government; that is why it is so important, in my opinion, to begin the process for a third bridge now. The traffic nightmares are increasing and becoming more frequent. Maintenance is more recurrent and costly. I have contacted our legislative officials on other occasions asking for their help and support, but all I get back is, “We are reviewing it”. In other words, we have better things to do with our time. This issue needs action and leadership now, not, “We are reviewing it.”


  3. Randy a subject matter that needs to be addrressed sooner then later.

    Outside of building new bridges that can accomidate trafic todays cars we have limited choices as to what can actuallt transpire.

    It goes with out saying that the first step is to close off exit one leaving the cape. When you see how one lane is supposed be how you get onto the bridge at that point, you realize that is not the case at all. it is like more then three different points of travel converge into two and then one. In some cases exit one has two cars trying to get into a single line of travel onto the bridge, further creating merging conditions at that point.

    Rerouting all off cape traffic between Quaker Meeting and the bridge that is heading off cape from route 6a onto route 6.

    Instead of having the route 6a traffic being allowed to drive all the way along route 6a until they get to the point at Exit one, neat Johns diner and the ball field.

    Place barriers at these locations only during the high volumn off cape traffic and force every one to stay on route 6.

    Stop the traffic on the service road as well during these times, especially the bus lines that have found another way to divert them selves from staying on route 6.

    Now as far as the bridges go , planning needs to begin on when and funding for at least one bridge that is more car friendly and at least 6 lanes wide. Given all of the bike traffic of late by having a fifth lane for just bikes , it could be utilized for car traffic when the demand warrants. The Bike road way could be used to get people off during high volumn use only.

    Action is needed now, rather then later, as time is running out when we here living on the cape may need to get off this island and we will be unable to do so and that is with out the tourists adding to a potentional catastrophe

    1. Greg, the original unless the guy claiming to be is more than 89 yr. oldJuly 23, 2013 at 6:34 AM

      I'm not sure I understand all that you have suggested, but I do think that re-routing traffic simply re-routes the problem as in several of the suggestions. The whole traffic pattern was built around the bridges and to dismantle it might cost as much as just building a new bridge. There is no cheep way out of this and with a total lack of leadership from uncaring Democrats that have a strangle on all of Massachusetts, I doubt we will see money for a bridge soon.

      I must say that you should be thanked for a comprehensive approach, perhaps it may work.

  4. Great overall look at the scenarios. No easy answers. Although 25 mile backups are an aberration; we have to look at 10-20 years from now. As the Cape becomes more populated, we need to look at a third bridge, since the existing bridges are now considered nonfunctional. It's the long range planning well into the future that needs to be addressed. Short term band aid approaches, like state police at the rotaries, or closing off the Christmas Tree Shop only exacerbates the problems causing traffic backups in other places. Best to look for long term solutions. Thanks for weighing in Randy! Well thought out.

  5. Hi Randy

    We need a third bridge, period. There are no quick fixes, so the sooner the better. You have detailed a number of the proposed options and issues that come along with these changes. While it is important to discuss these options, they will not help us travel off and on the Cape in times of high traffic volumes and emergencies. Last night (a Monday!), around 4:00 PM, there was a backup on Route 6 westbound from the Sagamore Bridge to Exit 2. The road was a parking lot. Why? I don’t know, but this is happening more and more often. Do these times get counted by those who think we are just a resort community?

    I would also like to weigh-in on the option of closing the on ramp from Cranberry Highway to Route 6 at the Christmas Tree Shop. I would be concerned that the traffic would now back up through Sandwich even greater as this option would be eliminated. Vehicles would only have the option of staying on Sandwich Road and going over the Bourne Bridge. This would make for increased traffic through Sandwich so vehicles would have to travel on Route 130 to get to Exit 2. This would allow them to get back on Route 6 to go over the Sagamore Bridge. This is not very appealing. Why do they not at least try closing the three access points from the Christmas Tree Shop parking area and Adams Street to the on ramp from Cranberry Highway? This would eliminate vehicles at least accessing Cranberry Highway at these points that add to the bottlenecks and increase in traffic trying to merge onto Route 6.

  6. Mr. Hunt,

    It may be time to think "out of the box" a little. As a short-term Cape resident I am just recently (the past three years) aware of the bridge traffic problems.

    I wonder what would happen if the bridges were to be divided into only three "extra-wide" lanes. Depending on the direction of the heavy traffic, they could be designated 'two off & one on' or 'two on & one off' for the duration of the heavy traffic week-ends. With the wider lanes and perhaps a slight increase in the bridge speed limit, the intimidation factor of the narrow lanes would be mitigated and possibly improve overall traffic. Could this plan be worth a trial on a not-too-busy week-end?

    I understand that this would be costly and labor-intensive for the State Police and unless trials show a vast improvement of traffic flow, not worth implementing.

    Thanks for reading this!

    1. You're onto something here. Believe it or not, somebody else brought this up in response to my piece and I ran the idea by a traffic engineer. You'd have to delineate the lanes somehow. If you use barrels, then you'd probably negate the desired effect of faster traffic. He also said that switching what is a routine for drivers is inherently dangerous and that the only acceptable method to swap lanes like this would be to use a zipper lane, like on the Southeast Expressway.

      His is just another opinion, of course.

  7. Here is a crazy idea: Add a road deck to the rail-road bridge in such a way that it could accommodate one lane of car traffic, without affecting its ability to provide a rail crossing. During peak times, open the rail bridge in one direction.

  8. Here is a crazy idea... Add a road deck to the train bridge such that it can carry a single lane of traffic, without affecting its ability to provide a rail crossing. Lower the bridge for one way traffic during peak periods.


    Build an inexpensive draw-bridge that would be lowered during peak traffic periods. It could remain up for most of the time so that marine traffic would be unimpeded.

  9. The DOT's concept of building a bridge parallel to the Sagamore has been unveiled. Who's for it? Got tolls?

  10. Randy progress at last? great idea on two bridges with wider travel paths would make for a faster and safer passage for those driving.
    The question of the toll will need to be very well discussed, especialy for those living on this side of the bridge that go shopping on the mainland side. It might be a good thing for economic development for those stores now set up on the island side [increased buying]
    Where will the funding come from, especially when we allready have so many bridges needed severe repairs throughout the state, where nothing is getting done , because of a lack of funding.
    Homeland security perhaps?

    Just think of how much money gets wasted as every one is stuck in long traffic lines now waiting to get Off cape along with the increased safety issues that presents as well.

  11. The cost of the bridge and maintenance would come from the tolls collected, according to the DOT's plan. As I described in this blog post, the likelihood of getting federal funding for such a project is next to nothing. That's why toll bridge is probably the only option for getting this project done within the medium-term.

  12. Another question since this bridge would be built mostly on Army Corp property, who would be the lead person to get it started?

  13. Could it be built such that one bridge, I assume the old one, could be used soley for cars coming off of tthe road in front of the Christmas Tree shop and the new bridge could be used for those coming down route 6 towards route 3. It would stop the bottle neck.

    1. The old bridge would handle traffic leaving the Cape. The four lanes would be converted to three lanes, the Christmas Tree Shop entrance traffic would use the right lane and the two Route 6 lanes would use the left two lanes. Most likely, the quick exit on the mainland side to Sorrenti's, Dunkin Donuts, McDonalds, etc., would be closed. Traffic would need the distance to the Bourne Scenic Highway exit in order to cross lanes without creating a bottle neck. Access to Friendly's, McDonalds, the P&B parking lot, etc., would come off of the Bourne Scenic Highway exit.

  14. It looks like 4 years since the last comment here we are still in the same situation. I think traffic should be restricted during predefined peak times, maybe Friday night, Saturday midday and evening, and Sunday evening. Several roads and exits/ramps should be closed. The Bourne rotary should be restricted so that it becomes a connector between rte 28 and the bridge. From the bridge drivers could exit around the state police station unto Sandwich Road heading north, and drivers from 28 could exit before the Dunkin Donuts to Sandwich road north. No interference with 28 and canal traffic flows.
    For Sagamore, heading unto the Cape, rte 3 traffic should continue in 2 lanes across the bridge, with no ramp from rte 6. For exiting the Cape, close Christmas tree and exit 1 entrance ramp, which will relieve the merging and also all the unwanted traffic on 6a in Sandwich by forcing traffic to enter rte 6 at exit 2 or further up the Cape as drivers will no longer see any benefit of traveling on 6a.
    Impacted business around Bourne rotary and the Christmas tree shop could get tax abatements as compensation.
    Nothing has to be built, we just would need the police to put up and take down barricades. A public education campaign would also be needed, along with road signs.



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