Rt 128 Interchanges

[JeffDowntown]

The adjacent exits are part/parcel inclusive of the reconstructions. Braintree Split project area was to treat the MA 37, Washington St./Quincy Adams, and Furnace Brook Pkwy. exits bounding its three sides with extra frontage work to eliminate weaving. Canton Split was to include a dedicated I-95 offramp for University Ave. to eliminate that weave and also complete the missing Dedham St. ramps on 95. Burlington Split fix was supposed to fix the horrible geometry and partially combine ramps for US 3 and Middlesex Turnpike. Don't know if we ever got far enough into final design to see the complete picture on Woburn, but given how utterly ad hoc the Washington St. ramps are something was due to be radically reorganized there.

In Woburn, you have problems on 95 on both sides of 93, Washington Street and Route 28 both mess with the flow.

Maybe I have always misinterpreted the talk about a "flyover". Maybe 95 thru traffic goes onto a mega flyover and the current surface lanes become a complex of entrance/exit merge lanes for 93, Washington Street and Route 28?

 

[F-Line to Dudley]

In Woburn, you have problems on 95 on both sides of 93, Washington Street and Route 28 both mess with the flow.

Maybe I have always misinterpreted the talk about a "flyover". Maybe 95 thru traffic goes onto a mega flyover and the current surface lanes become a complex of entrance/exit merge lanes for 93, Washington Street and Route 28?

Project area is inclusive of Washington and 28. One of the things they do plan to do regardless of final 93 interchange design is extend 8-lane territory on 128 two miles further east to the MA 129 exit. That'll necessitate wholesale rebooting of 3 interchanges to the east: 28, North Ave., and 129. Possibly results in getting 8 lanes extended all the way to Peabody Split, as it looks like most of the bridges to the east are already pre-widened for it. Washington I gotta think can be treatable with collector-distributors or frontages, as it's got plenty of insertion angles that don't have to mash directly into the mainline. 28 has plenty of real estate on its currently malformed cloverleaf to reimagine at less unbelievably shitty LOS.

 

[AndrewOnTheMBTA]

This is what they did for those interested:

View attachment 13227

Asked my Traffic Engineer friend why this was done. This design eliminates the weaving on both I-95 and MA 9 caused when those exiting in the beginning of the clover interfere with the second part of the clover (referring the horrid middle section between the on ramp and off ramp of the clover). It's to my knowledge that this is why clover leafs are less and less common in highway design

 

[mass88]

Asked my Traffic Engineer friend why this was done. This design eliminates the weaving on both I-95 and MA 9 caused when those exiting in the beginning of the clover interfere with the second part of the clover (referring the horrid middle section between the on ramp and off ramp of the clover). It's to my knowledge that this is why clover leafs are less and less common in highway design

Cloverleafs are a poor design. The changes made at this interchange make it easier, and safer to get onto 95 and exit 95. I'd like to see the small stretch up 95, where you have people getting onto 95 north from rte 16 and at the same time people trying to exit to both Grove st and also the Pike all within a very short stretch.

 

[chmeeee]

I suppose you could make it a giant four way stop to get that number to 0 but how efficient would the traffic flow be? I used to drive through there everyday and found it very aggravating. The cloverleaf worked fine.

So an 87% reduction in crashes is no good because you're aggravated?

 

[real_EthanHunt]

this seems pretty obvious at this point, but to be sure, fixing the cloverleaf weave on 95 was MassDOTs major concern (as shown from the crash history) not operations on Rt 9.
Yes it is ideal to have the left turns at the end of the off ramps and not onto the on ramps (as shown in post 10), but that wasnt possible in this location (office building on the NW corner and that former SB on ramp loop not big enough radius to meet standards).

 

[North Shore]

Cloverleafs are a poor design. The changes made at this interchange make it easier, and safer to get onto 95 and exit 95. I'd like to see the small stretch up 95, where you have people getting onto 95 north from rte 16 and at the same time people trying to exit to both Grove st and also the Pike all within a very short stretch.

Cloverleafs work - provided traffic flow is inherently low and provides sufficient gaps in the flow to allow for weaving. Which is why 128 was constructed with so many of them at its interchanges.

As soon as traffic increased, they became problematic. You just cannot process vehicles efficiently with them. Bypass ramps work so much better.

 

[Charlie_mta]

I want one of these constructed at a Rte. 128 interchange:

 

[jklo]

That looks like an incredible waste of space.

 

[jbray]

That looks like an incredible waste of space.

A diverging diamond has one of the smallest footprints for a freeway intersection; certainly smaller than the clover. That median isn't required.

 

[millerm277]

A diverging diamond has one of the smallest footprints for a freeway intersection; certainly smaller than the clover. That median isn't required.

Although they do usually route the pedestrian/cyclist path through the median, so some median is required, especially to not make it particularly unpleasant for them.

(I agree with your overall point regarding footprint).

 

[mass88]

I want one of these constructed at a Rte. 128 interchange:

This is an interesting design, and one that is becoming more common in other parts of the country. It doesn't look too land intensive either.

 

[Charlie_mta]

This is an interesting design, and one that is becoming more common in other parts of the country. It doesn't look too land intensive either.

Here's a more compact version of a diverging diamond interchange in Washington State. I could see something like this one fitting into the existing footprint of a cloverleaf interchange. Click on the photo to zoom in on the bike lane marking details, etc..

https://flic.kr/p/2jvUPjm

 

[DZH22]

I don't see how anything that requires red lights could possibly work at the 93/95 interchange. While the cloverleaf is admittedly terrible, my bigger problem with the area is the lane drop on 95 directly north of 93. For most of the day there's a 1-2+ miles traffic jam heading north until you get past Route 28.

 

[Charlie_mta]

I don't see how anything that requires red lights could possibly work at the 93/95 interchange. While the cloverleaf is admittedly terrible, my bigger problem with the area is the lane drop on 95 directly north of 93. For most of the day there's a 1-2+ miles traffic jam heading north until you get past Route 28.

These are not intended for expressway-to-expressway interchanges, only for non-expressway roads intersecting with an expressway.

 

[DZH22]

These are not intended for expressway-to-expressway interchanges, only for non-expressway roads intersecting with an expressway.

It seems like something better suited for Route 2 (west of 95) or maybe Route 9, as opposed to the more major interstates. Adding traffic lights to 90, 93, or 95 would be the death of the highways. (yes, I know 90 had the tollbooths, but red lights would still be worse)

 

[F-Line to Dudley]

I don't see how anything that requires red lights could possibly work at the 93/95 interchange.

Absolutely no one suggested that was a relevant application. Interstate-to-interstate quite clearly needs total unsignaled limited access. DD's are a potential solution to bad cloverleaf design at exits to arterials.

While the cloverleaf is admittedly terrible, my bigger problem with the area is the lane drop on 95 directly north of 93. For most of the day there's a 1-2+ miles traffic jam heading north until you get past Route 28.

Already covered. The official MassHighway plan, regardless of final ramp design, is to extend 8-lane territory at least as far east as the MA 129 interchange 2 miles away.

 

[Charlie_mta]

It seems like something better suiting for Route 2 (west of 95) or maybe Route 9, as opposed to the more major interstates. Adding traffic lights to 90, 93, or 95 would be the death of the highways. (yes, I know 90 had the tollbooths, but red lights would still be worse)

All the red lights are on the road intersecting the expressway. There aren't any traffic lights on the expressway itself.

 

[F-Line to Dudley]

It seems like something better suiting for Route 2 (west of 95) or maybe Route 9, as opposed to the more major interstates. Adding traffic lights to 90, 93, or 95 would be the death of the highways. (yes, I know 90 had the tollbooths, but red lights would still be worse)

Why is this a thing to keep getting hung up on when (1) that's not at all what's in ANY of the 93/95 concepts; (2) the discussion was a breakout from the Route 9 cloverleaf tangent, the exact arterial interchange situation you claim where it would be appropriate; (3) traffic lights quite clearly break the expressway-to-expressway interface so aren't a thing that'll ever (illegal grandfatherings like 90/291 aside) be permissible and thus are not a thing to waste energy expressing concern over? Are you reading this thread at all before responding??? These aren't legit traffic engineering concerns you're citing here. Wrong bucket entirely.

 

[DZH22]

Are you reading this thread at all before responding???

Skimmed through, but I'm still confused by the picture in Post 28 because the highway doesn't appear to be buried there like the one in Post 33. Maybe that's supposed to be an overpass and it just isn't obvious?