I mentioned this on another thread, but is there any reason the New Jersey Turnpike Authority has never considered separating the on and off-ramps of rest areas for the car & truck lanes?
Not sure if I understand your question, but within the dual-dual setup, service areas on the New Jersey Turnpike have access ramps from both the car lanes and the truck lanes, as do the ramps from the service areas back to the turnpike.
What would be the benefit? Having one ramp that splits seems to work just fine.
If you mean having actual separate truck and car parking areas, such that the car area is only accessible from the car lanes, consider that a good number of cars use the truck lanes anyway.
Plus, it is possible that all traffic could be shifted onto only one roadway during a major accident or major construction.
Quote from: Duke87 on March 26, 2011, 09:29:51 PM
What would be the benefit? Having one ramp that splits seems to work just fine.
No risky merges between the cars only ramps and the cars, trucks and buses ramps are one.
I can see the merit in your idea, but as mentioned previously, we close certain carriageways frequently for accidents, congestion or maintenance. Now that the weather's breaking (finally!), we've had closings much more frequently, and sometimes closing a roadway on each direction at the same time. Patrons have hard enough times finding a single exit ramp, much less multiple ones.
I don't think forcing cars to drive through the truck parking area to get to the outer truck lanes is a great idea either. We've all seen how most people drive around trucks.
Actually drove it a couple of days ago..It seems to be a work in progress and I got the impression they're focussing on exits and I think they'll go back and do the service areas. I forgot how much traffic that road actually carries. You can see they are actually clearing more right-of way. For the amount of volume, it's really not a bad road.
Quote from: ATLRedSoxFan on March 28, 2011, 10:02:41 AM
Actually drove it a couple of days ago..It seems to be a work in progress and I got the impression they're focussing on exits and I think they'll go back and do the service areas. I forgot how much traffic that road actually carries. You can see they are actually clearing more right-of way. For the amount of volume, it's really not a bad road.
The big project now is the widening between exits 6 and 9. We're adding 1 lane on each truck (outer) roadway and extending the car and truck lanes (inner and outer, respectively) from exit 8A down to exit 6, and the two will merge just south of there. They have portions of the new outer roadways laid already just south of Interchange 8. I drive this every day and with the trees cleared it's definitely a different view. The huge electric towers are now in your face, in addition to many buildings that were hidden by the trees. Once the widening is complete the current roadway in that area, which will be the new inner roadway, will be closed and rehabilitated.
The big choke points are mostly on weekends and holidays. Most notably is the merge of the car and truck lanes southbound, but also northbound anywhere between exit 6 and the car/truck split. Believe me, that always makes for a fun commute, as during summer weekends I always have to take alternate routes. I work for the highway, so I can't use "I didn't know there was congestion" as an excuse. ;)
Quote from: ATLRedSoxFan on March 28, 2011, 10:02:41 AM
Actually drove it a couple of days ago..It seems to be a work in progress and I got the impression they're focussing on exits and I think they'll go back and do the service areas. I forgot how much traffic that road actually carries. You can see they are actually clearing more right-of way. For the amount of volume, it's really not a bad road.
Nah, service areas are being done simultaneously.
Quote from: tollboothrob on March 28, 2011, 07:03:35 PM....
The big choke points are mostly on weekends and holidays. Most notably is the merge of the car and truck lanes southbound, but also northbound anywhere between exit 6 and the car/truck split. Believe me, that always makes for a fun commute, as during summer weekends I always have to take alternate routes. I work for the highway, so I can't use "I didn't know there was congestion" as an excuse. ;)
Regarding the location mentioned in the bolded text (just to the south of Exit 8A), I've always wondered why the merge was configured so that the two center lanes merge into a single lane. I assume the thought process had something to do with not wanting all the outer-carriageway (Cars/Trucks/Buses) traffic to have to merge left while at the same time not wanting to drop the two left lanes on the inner (Cars Only) carriageway, but I've always thought it's a very peculiar design to have the two center lanes of a highway merge in that fashion. Do you happen to know why it's that way and whether the new southern end of the quad-carriageway system will use the same sort of configuration?
(I haven't driven on the southbound Turnpike through there in years, probably not since 2003, simply because of the traffic. The construction will ensure that I use the I-78 route for the foreseeable future.)
Quote from: 1995hoo on May 09, 2011, 02:58:38 PM
Quote from: tollboothrob on March 28, 2011, 07:03:35 PM....
The big choke points are mostly on weekends and holidays. Most notably is the merge of the car and truck lanes southbound, but also northbound anywhere between exit 6 and the car/truck split. Believe me, that always makes for a fun commute, as during summer weekends I always have to take alternate routes. I work for the highway, so I can't use "I didn't know there was congestion" as an excuse. ;)
Regarding the location mentioned in the bolded text (just to the south of Exit 8A), I've always wondered why the merge was configured so that the two center lanes merge into a single lane. I assume the thought process had something to do with not wanting all the outer-carriageway (Cars/Trucks/Buses) traffic to have to merge left while at the same time not wanting to drop the two left lanes on the inner (Cars Only) carriageway, but I've always thought it's a very peculiar design to have the two center lanes of a highway merge in that fashion. Do you happen to know why it's that way and whether the new southern end of the quad-carriageway system will use the same sort of configuration?
(I haven't driven on the southbound Turnpike through there in years, probably not since 2003, simply because of the traffic. The construction will ensure that I use the I-78 route for the foreseeable future.)
Yes, the southern end will be similar - except a 3/3->3 merge instead of a 3/2->3 merge. So you'll have three sets of merging lanes 2->1 (cars left/center, trucks center/right, and the middle 2 lanes).
The reason it's done as it is now - only the Turnpike Authority really knows. I would probably have merged the car lanes down to 2, brought 2 and 2 together, then ended the right lane downstream. In the future case, I'd probably have both sets of lanes split 2/2 (2 SB, 2 WB) given that the PA Extension is due to be completed as I-95 soon. Then it's a simple 2/2->4->3 merge each way. Of course, the NJTA doesn't want to split lanes on the mainline, they want dedicated right exits. Okay, fine, then just end the right lane in each roadway (3->2) then the same 2/2->4->3 merge I described. But I'm not in charge.
Jumping on this thread rather late, but at one of the local meetings prior to the start of any construction, I asked the very question about the merge at the car/truck lanes (the turnpike actually knows them as SNI, SNO (South to North Inner & Outer Drives), NSI and NSO (North to South Inner & Outer Drives). A representive of the turnpike stated that their studies showed that a merging of two lanes at once produced fewer lane merges and allowed traffic to flow at a more steady pace than trying to merge one lane into another, then that lane again into another - regardless if it was a right lane end or left lane end. Again, as mentioned before, only the turnpike powers-to-be know the real reason.
For the 3x3 drives, in most cases car/trucks/buses will only be in the 2 right lanes of the outer drive, so they will merge into one lane, and cars will exclusively use the Left and center lanes of the inner drive, and the right lane of the inner drive and the left lane of the outer drive. And having said all of that, traffic volumes drop dramatically below interchange 6. The merge will be 2 miles below the interchange, so except for the heaviest travel weekends and holidays, it shouldn't be a problem.
I also inquired about the lack of acceleration lanes (the turnpike typically has long decel lanes, but non-existent accel lanes). Part of the widening project will include longer accel lanes. Actually, many of the onramps in the construction zone have temporary lengthened accel lanes already...the exact opposite of many construction zones where there are stop signs at the end of the ramps!
One final note for now: One reason the turnpike doesn't know the lanes as car and car/truck/bus lanes is that at any time a ramp is closed from an interchange or service plaza to the outer drive, trucks are permitted from the interchange onto the inner drive, and are not forced to exit that carriageway. After the widening project, that would mean any of 14 interchanges and 3 service plazas along the dual-dual section could have a ramp closure that would lead to trucks using the 'car' lanes.
Just one bit of clarification, it's not there are "no accel lanes," it's that the Turnpike typically uses a tapered accel lane, which is perfectly permissible by the MUTCD, instead of the more typical parallel accel lane.
Quote from: jeffandnicole on August 02, 2011, 08:00:18 PM
One final note for now: One reason the turnpike doesn't know the lanes as car and car/truck/bus lanes is that at any time a ramp is closed from an interchange or service plaza to the outer drive, trucks are permitted from the interchange onto the inner drive, and are not forced to exit that carriageway. After the widening project, that would mean any of 14 interchanges and 3 service plazas along the dual-dual section could have a ramp closure that would lead to trucks using the 'car' lanes.
One thing I think ought to happen once the new VMSes are up and running is if there is a outer ramp closure before a service plaza, have the signs display something along the lines of "ALL TRUCKS AND BUSES MUST EXIT AT SERVICE AREA" in the inner lanes so they can transfer to the outer lanes without having to exit the system (but having to slow down and possibly get stuck in truck traffic at the rest area).
Why? The inner roadway can handle trucks.
Quote from: Steve on May 09, 2011, 07:02:54 PM
Quote from: 1995hoo on May 09, 2011, 02:58:38 PM
Quote from: tollboothrob on March 28, 2011, 07:03:35 PM....
The big choke points are mostly on weekends and holidays. Most notably is the merge of the car and truck lanes southbound, but also northbound anywhere between exit 6 and the car/truck split. Believe me, that always makes for a fun commute, as during summer weekends I always have to take alternate routes. I work for the highway, so I can't use "I didn't know there was congestion" as an excuse. ;)
Regarding the location mentioned in the bolded text (just to the south of Exit 8A), I've always wondered why the merge was configured so that the two center lanes merge into a single lane. I assume the thought process had something to do with not wanting all the outer-carriageway (Cars/Trucks/Buses) traffic to have to merge left while at the same time not wanting to drop the two left lanes on the inner (Cars Only) carriageway, but I've always thought it's a very peculiar design to have the two center lanes of a highway merge in that fashion. Do you happen to know why it's that way and whether the new southern end of the quad-carriageway system will use the same sort of configuration?
(I haven't driven on the southbound Turnpike through there in years, probably not since 2003, simply because of the traffic. The construction will ensure that I use the I-78 route for the foreseeable future.)
Yes, the southern end will be similar - except a 3/3->3 merge instead of a 3/2->3 merge. So you'll have three sets of merging lanes 2->1 (cars left/center, trucks center/right, and the middle 2 lanes).
The reason it's done as it is now - only the Turnpike Authority really knows. I would probably have merged the car lanes down to 2, brought 2 and 2 together, then ended the right lane downstream. In the future case, I'd probably have both sets of lanes split 2/2 (2 SB, 2 WB) given that the PA Extension is due to be completed as I-95 soon. Then it's a simple 2/2->4->3 merge each way. Of course, the NJTA doesn't want to split lanes on the mainline, they want dedicated right exits. Okay, fine, then just end the right lane in each roadway (3->2) then the same 2/2->4->3 merge I described. But I'm not in charge.
We tried your suggestion for the south end during our Interchange 6 design, but the Authority wanted the greater "capacity" of the three lane sections approaching the merge. Capacity here means storage space when the area is congested. I never quite understood that . . .
Similarly, the Authority has always talked about balance regarding merging or expanding lanes. The idea was always that each lane would make one merge or diverge. Notice also the ramp merges where two two-lane ramps merge to a three lane section. The inside lanes are the ones that merge. I never cared for that.
I think it all boils down to a perceived smoother operation if either barrel of the dual-dual section (or one of the spurs further north) needs to be closed.