Sullivan Square isn't "before the city", it is the city.
Traffic backs up in every single direction stemming out of there. A garage would add more volume and points of conflict to this.
Sullivan and all its associated roads and parking lots are getting blown up and redeveloped.
The land there is too valuable to use for car storage. Its the next large frontier for large scale development, and that's wayyyyyy more important then parking.
Wellington is 20 seconds away.
The whole McGrath is an induced demand trap, creating traffic and crushing Sullivan for no reason other than that's what's always happened. Straight up eliminating it and reconfiguring the 93 access ramps to 16, and upgrading 16 is the logical thing to do. Trying to stuff more things into something that already doesn't work is not.
Btw, I really shouldn't need to keep saying this, but I own a car. I love it. I drive it to get out of the city, and sometimes just to cruise around. But I don't use it to get to work, or when there is traffic, because it makes no fucking sense.
Also F-Line, would you mind bullet pointing and PMing me your 93/16 reconfiguration? I'm working on a whole McGrath thing and am just starting to get to the Fellsway, and you've done more leg work than I.
There's really not much to the 93/16 reconfig if you're just drawing it on a map. But here's the point-by-point + fine print of how to build it, how the pieces fit together, and how the geometry as-constructed works within the somewhat tight spaces around the river.
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#1. 16W to 93S
-- At the current traffic light where the 16E collector road + 93S-to-16E offramp meets mainline 16, drop a 93S onramp immediately across. tied into the same traffic signal.
-- To get the alignment more or less straight across from the existing collector road interface and square the angle for the left turn off 16W, take the rear Bank of America and Pizza Hut parking lots.
Note 1: Frankly, I don't think either building is long for this world since BoA is closing full-service locations all over the place in a cost-cutting move and Pizza Hut is...well, Pizza Hut, which isn't nearly the chain it was 20 years ago. Both those buildings will meet the wrecking ball on their own if you just wait long enough. So accelerate that process with these cost-slashing chains-o'-crap. Something much more tasteful will get built in their place facing Mystic Ave. in more friendly fashion.
Note 2: Those buildings being somewhat 'livelier' in the mid-70's was probably why this ramp was never built in the first place. So the reason for its absence was much more era-specific than specific blockers.
-- Reconfigure the lane split for when the 16W frontage road splits off and from the mainline stub to Mystic Ave. The two lanes divide into single-lane splits, and then post-split each single lane immediately re-divides into two. In other words, match the setup of the collector road's lane split on the mainline stub. Now you have proper traffic sorting for the split all the way back to the Meadow Glen Mall light. Honestly, do this today because it would correct the weaving mishmash at no loss of capacity with the 2-lane re-divide being matched on each side of the split.
-- When the lanes re-divide into 2 on the mainline stub post-split, left lane is the turn lane for 93S, right lane is straight for Mystic Ave. This gives you a 700 ft. super-long turning lane that'll absorb any queue. The Mystic-bound right lane isn't any capacity reduction because it re-divides into 2 once more past the traffic light. You just no longer need such a long queue length at Mystic because the 93S traffic is bailing out early instead of plowing all the way to McGrath.
-- Squeeze the median immediately after the overpass to get the left lane on-trajectory for the entrance ramp now covering the BoA rear lot. Maybe traffic-island the diverging straight-ahead Mystic-bound traffic in the right lane to accomodate this last-minute shift.
Note 3: This little 'shimmy' does some extra correction for the sharpness of the left-turn angle. The angling through the Pizza Hut + BoA lots corrects for the rest. So you'd have maybe an 100-degree angle left turn...slightly better than a right angle. The extreme length of the left-turn back to the other side of the bridge is what prevents the queue length from getting problematic when a big rig or something is making a turn. i.e. This is prevents the awfulness of the lefts at the Mystic/McGrath intersection + U-turn from 'metastasizing' to a new location.
-- Traffic-island right onto 93S for the relatively meager volumes coming from Mystic Ave.
Note 4: Remember, Mystic already has direct access to 93S at Medford Sq. on one side and straight-ahead at the McGrath light on the other, so the existence of this new entrance draws all its volume from 16W and bupkis in the other direction. No special provisions necessary other than a simple traffic-island right for bailing onto 93 before the stop line at the light.
-- Onramp quickly compacts from point of origin in the BoA parking lot to pull up right alongside 93 (through the makeshift and probably squatter/illegal boat parking 'lawn'). Merge. Delete the Mystic Ave. offramp to claim that offramp decel lane as the onramp accel lane. Thus requiring zero widening of 93 itself for the merge.
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#2. 93N-to-16E
-- On 93N, delete the Mystic Ave. onramp where it pulls up alongside the MassHighway storage yard to merge. Trade in that merge/accel lane running space for the decel lane to 16, so no widening of 93 is required.
-- Send the ramp down the hillside in a compact setup on trajectory as if it were going to stop at a traffic light squared up with the 16W collector.
-- Have a right-turn traffic island at bottom of the hill (i.e. like the 16E collector road does on the other side of the overpass for turning the Mystic Ave. direction). Only instead of having an intersection (because you can't turn left), funnel all traffic through that little traffic island-esque hook onto 16E with a short merge lane.
Note 1: You have to keep the setup compact here to avoid taking any adjacent park space. Hence, the little hook-shaped traffic island merge and not a sprawling high-speed interchange like the 16W-to-93N peel-out on the other side. 16E, however, is very slow-speed here because the traffic light is right on the other side of the overpass 500 ft. away. Therefore you do not need high-speed geometry or high-speed accel lane for the merge and can keep the ramp compact with traffic island-esque geometry on the 16E merge.
-- Reconfigure the median on 16 and Meadow Glen Mall left-turn lanes to straighten the 16E carriageway and eliminate the curve that would otherwise compromise this exit ramp's interface with 16E. After 16E emerges from the underpass, shift it to the median (i.e. eliminate the grass and the wide concrete median on the Mystic Bridge for a short stretch of jersey barrier) to square up the angle and create room for the hook merge.
Note 2: The Mystic Bridge was replaced in the (late-80's?) with the much-widened current span. This is probably why the offramp ramp was not pre-existing in the mid-70's...per Historic Aerials there was no freaking way the 16E geometry around that median was modifiable around the old extremely narrow previous drawbridge. Another of-its-era omission that is not a present-day blocker.
-- Compact the protected left-turn lanes for Meadow Glen Mall from 2 lanes to 1. When the Mall was first built they thought it would be a much higher-traffic destination than it turned out to be. Much like the 2 turn lanes on Fellsway for Assembly. So 1 protected left is adequate. Use the freed-up space on the Mystic bridge for the merge off the new 93 exit and the shift off the median realignment onto current alignment. Should leave equivalent left-turn space for Meadow Glen. Prohibit crossing lanes from the new 93 merge all the way to the Meadow Glen lane. Make them pull a uey a bit downstream and backtrack to the 16W split for Meadow Glen.
Note 3: Keeps you from introducing any very dangerous weaving. Keeps the sorting orderly for the merge into thru 16E traffic. And traffic volumes from at the single left-turn lane to the Mall reasonable and not 1 car heavier than they are today. We know 1 turn lane should be adequate today based on traffic levels to the Mall and Shaw's, so we are not taking a risk on future volumes by deleting left-turn lane #2.
-- As noted, shiv a uey downstream at a wide-ish point on the median for back-track access to the Mall from this new 93 exit. Well downstream, so the weaving isn't problematic on either side. Or maybe re-jigger the Commercial St. intersection so the wide breakdown lane collapses and creates more room on the (extremely low-volume) protected left for a signalized U-turn. Cars-only, because trucks can use more turning radius-appropriate Wellington Circle if they need to backtrack for deliveries to the Mall.
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#3.
16W-to-93N
Dirt simple in concept, slightly complicated for EIS'ing.
-- On the 16W collector road, take the right lane (out of 3 incredibly low-volume total lanes) for a split onto 93N.
-- Drop the ramp off the hillside just as the collector road starts to get steeper into its curve.
You don't have an opportunity to widen the 93 Mystic bridge for an accel lane, so you need to pull some tricks:
-- On the southbound side, extend the (way too short) Route 60 onramp accel lane +6 stripes to get it closer to the bridge.
-- Re-stripe 93 SB to cannibalize the SB breakdown lane over the bridge. Traffic entering from 60 has now sorted itself and has much longer accel space to do so, so the loss of 400 extra feet of breakdown lane is no loss. In fact, it's a net gain overall because of the 60 accel lane extension.
-- Move the center jersey barrier on the bridge in the middle of what's now the SB left lane to create extra room on the NB carriageway. Shift the highway *so* gradually from the adjacent 16W overpass to the south and 60 bridge to the north that the geometric shift is utterly unnoticeable.
-- Reclaimed space on the NB side is for the accel lane from 16W. Remember, merges don't have breakdown lanes so you are only banking the current NB breakdown lane + the few feet of jersey barrier shifting to come up with a 12 ft. lane. (Hence, the absolutely unnoticeable geometry of the 'shift' when you move the jersey barrier onto the re-claimed SB space.)
-- Accel lane stays intact up to the Route 60 split (i.e. once it's merged in the 60 exit gets signed "Right Lane - Exit Only".) A little under a half-mile of total lane space, which is enough for the traffic sorting. Rebuild the ramp geometry of the 60 exit, which is as deficient on the NB side as it is on the SB side.
Note 1: You may need to graft on a little 'addendum' to the 93 Mystic bridge for the direct interface with this new onramp. But only over dry land on the south shore of the river (i.e. over the future walking path extension), not over water itself. Will add some cost and some extra EIS'ing, but the ramp is on the 93N carriageway by the time the bridge crosses water (plus the re-claimed pavement handles the accel lane) so there's no actual constrained geometry at the interface.
Note 2: Because of closeness to the riverbank and wetlands the ramp--even at a mere 800 ft. total length from where it interfaces with the 16W pavement to interfaces with the 93N pavement--is going to be a time-consuming EIS. And definitely the most expensive part of the build. But it's still very minor and short money in the grand scheme of things, so I don't really see any blockers. We're doing more invasive stuff around longer linear quantities of wetlands for the 128 add-a-lane.
And that's it. The rest of the casino route comes from changing the balance at Wellington Circle to weight much heavier in the 16 E-W direction by pursuing load reduction on Fellsway (some of which is accomplished by this ramp job alone). Creating the casino back-door driveway off the Gateway Ctr. access road. And de-WTF?-ing the distended Santilli rotary so the Gateway rotary is much more single-focused on Gateway + casino traffic and the 99 rotary much more single-focused on 99 traffic. No longer Siamese twins = significantly cleaned-up flow = higher capacity here. To go with the higher 16 capacity + flow at Wellington Circle. To go with the high-capacity 93 pipe.
