Navigation System's effect on congestion at highway incidents

[Brian556]

I've never used or ridden in a vehicle with a navigation system, so I'm not fully aware of their functionalities. It is my understanding that they can tell you if there is congestion ahead, and suggest an alt route.

This seems to be having a significant impact on traffic around highway incidents. Because of these systems, more drivers are choosing an alternate route.
This is causing way more congestion on the alternate routes than there used to be, but, on the flip side, is making the backup on the freeway much less severe, to the point that it's now seems to be better to just sit through the backup.

This has been observed by a local city as well. Corinth has observed this happening to the point that they now need a signal at an intersection far from the freeway partially due to drivers detouring around congestion on I-35E.

Of course, it sucks that the alternate routes that I used to use all the time are now congested with non-local drivers who can now find them with the navigation systems.

A good side to this is that the navigation systems can provide load-balancing between more than none route, much like some computer network protocols. Once the majority of vehicles have this in them, we will be able to make more efficient use of the roads we have, and be able to mitigate congestion much better.

[SteveG1988]

My GPS isn't 100% accurate since it uses the FM radio based traffic service. So it gets told there is a jam between A and B on the highway, downside is that not all areas have a station broadcasting it that is in range of the highway that has the issue.

[ET21]

The system has gotten better over the years, still has limitations though. I still would go to AM radio first

[SSOWorld]

I avoid the AM radio because I prefer not to listen the other garbage it presents. (personal preference) and preferred the XM channels while living out west.  I've set up my phone with Google maps showing an overhead live follow and though it wasn't perfect at the time (still isn't) it worked for the job it did since had driven the 5 through the Newhall pass interchange daily at the time between the 210 Yarnell in Sylmar and Magic Mtn Pkwy in Valencia.

Outside of that, I've only mounted it during trips through large cities.

[SteveG1988]

Waze is pretty good about traffic.

[realjd]

If every car has live traffic data and can make real-time route adjustments to compensate, the end result is optimal use of the roads. In your example where the side road is getting more heavily used, that's exactly the way that it's supposed to work. The side road had additional unused capacity when the main road is over capacity, so siphoning cars onto the alternate route makes sense. If that road gets too clogged, cars will choose to go back to the main road or find another alternate route.

[MikeTheActuary]

My Subaru Forester's satnav relies on traffic data delivered by XM (if you subscribe).  Outside the major metro areas where where SiriusXM focus their traffic resources, it's almost useless -- you get data on some incidents, but no congestion information (and therefore no ability to determine whether an alternate route is an option).

So, on days where I'm doing the 115 mile commute into the Boston metro area, I'll just pop open Google maps and take a quick glance at the traffic displays to see if an alternate route is viable.  On weekdays, the answer is generally not (unless I get a heads up about something truly nasty, justifying going 95»495»Pike, rather than 128»Parking Lot Formerly Known as the Pike) -- enough traffic diverts to the alternates to make them almost worthless.   On weekends, however, when there are more sheeple on the roads, awareness of and/or guidance to alternate routes is still useful.

I'd say that for regular commute situations, the increased availability of traffic data is probably helping load-balance the highways. On amateur drive days...not so much.

[cpzilliacus]

I've never used or ridden in a vehicle with a navigation system, so I'm not fully aware of their functionalities. It is my understanding that they can tell you if there is congestion ahead, and suggest an alt route.

If you have an Android or Apple smartphone, you can download the Inrix application that shows speeds on most freeways, expressways and arterials.  It words decently for freeways, but IMO has some latency problems on arterials.  This is not the only application available that provides such information, but it is the one I use currently.

This seems to be having a significant impact on traffic around highway incidents. Because of these systems, more drivers are choosing an alternate route.
This is causing way more congestion on the alternate routes than there used to be, but, on the flip side, is making the backup on the freeway much less severe, to the point that it's now seems to be better to just sit through the backup.

I have observed such driver behavior for many years as the result of radio traffic reports, but it may well now be happening with applications like Inrix (which come built-in with some new vehicles).

But the bigger impact I have seen in the D.C. area is from GPS units generally, advising drivers to take the shortest route as an alternative to I-95, which is (in many cases) much more congestion-prone than staying on I-95.

This has been observed by a local city as well. Corinth has observed this happening to the point that they now need a signal at an intersection far from the freeway partially due to drivers detouring around congestion on I-35E.

Of course, it sucks that the alternate routes that I used to use all the time are now congested with non-local drivers who can now find them with the navigation systems.

A good side to this is that the navigation systems can provide load-balancing between more than none route, much like some computer network protocols. Once the majority of vehicles have this in them, we will be able to make more efficient use of the roads we have, and be able to mitigate congestion much better.

I have not observed bail-out traffic so severe that new signals were required, but then most places were signals might possibly be warranted already have them, at least around here (Md., Va. and D.C.).

[1995hoo]

Some sat-navs can give you traffic info, some can't. The one built into my Acura predates that capability. If I have a route programmed I can tell it "Detour" and it'll plot an alternate route, but it won't consider traffic or the like. I still prefer using it, with the joystick below the screen making it easy to pan the map around, over a purely touchscreen system.

I doubt I'll ever understand how navigation devices decide what roads to recommend, though. It's clear to me, based on some of the strange routings I've been offered both by my system and my wife's Garmin, they must have some sort of hierarchy that causes them to disregard secondary routes in most instances even when such routes would be the most direct way, but I haven't been able to figure out where the tipping point is that will cause them to select a secondary route over a primary route–that is, at what point does the primary route become too far out of the way? I guess I should be happy about that, though, because it means the sat-nav diehards don't use a lot of my favorite shortcuts and back routes!

[jwolfer]

Some sat-navs can give you traffic info, some can't. The one built into my Acura predates that capability. If I have a route programmed I can tell it "Detour" and it'll plot an alternate route, but it won't consider traffic or the like. I still prefer using it, with the joystick below the screen making it easy to pan the map around, over a purely touchscreen system.

I doubt I'll ever understand how navigation devices decide what roads to recommend, though. It's clear to me, based on some of the strange routings I've been offered both by my system and my wife's Garmin, they must have some sort of hierarchy that causes them to disregard secondary routes in most instances even when such routes would be the most direct way, but I haven't been able to figure out where the tipping point is that will cause them to select a secondary route over a primary route–that is, at what point does the primary route become too far out of the way? I guess I should be happy about that, though, because it means the sat-nav diehards don't use a lot of my favorite shortcuts and back routes!

Those of us on here are a minority in the fact that we could navigate without GPS. I use GPS/ google maps/Waze to check on traffic. And for fun see how long it takes GPS to recalculate when going off "approved " route.

The definitely default to interstates

[1995hoo]

Some sat-navs can give you traffic info, some can't. The one built into my Acura predates that capability. If I have a route programmed I can tell it "Detour" and it'll plot an alternate route, but it won't consider traffic or the like. I still prefer using it, with the joystick below the screen making it easy to pan the map around, over a purely touchscreen system.

I doubt I'll ever understand how navigation devices decide what roads to recommend, though. It's clear to me, based on some of the strange routings I've been offered both by my system and my wife's Garmin, they must have some sort of hierarchy that causes them to disregard secondary routes in most instances even when such routes would be the most direct way, but I haven't been able to figure out where the tipping point is that will cause them to select a secondary route over a primary route–that is, at what point does the primary route become too far out of the way? I guess I should be happy about that, though, because it means the sat-nav diehards don't use a lot of my favorite shortcuts and back routes!

Those of us on here are a minority in the fact that we could navigate without GPS. I use GPS/ google maps/Waze to check on traffic. And for fun see how long it takes GPS to recalculate when going off "approved " route.

The definitely default to interstates

It's interesting, I can set mine to "Avoid Freeways" or "Avoid Toll Roads" provided the trip is less than 100 miles. If it's more than 100 miles, those options aren't available. But even if I do select those options it still sometimes goes for a longer route than I'd select because its programming must be set to avoid roads of "too low" a grade. I guess I can understand why they generally don't route you down neighborhood streets and on the whole I'd say that's probably for the best. But how they decide what priority to give a road has never been clear to me.

[SSOWorld]

{{omit for emphasis}}

Those of us on here are a minority in the fact that we could navigate without GPS. I use GPS/ google maps/Waze to check on traffic. And for fun see how long it takes GPS to recalculate when going off "approved " route.

The definitely default to interstates

Why Waze? Such a poor choice 

[hbelkins]

{{omit for emphasis}}

Those of us on here are a minority in the fact that we could navigate without GPS. I use GPS/ google maps/Waze to check on traffic. And for fun see how long it takes GPS to recalculate when going off "approved " route.

The definitely default to interstates

Why Waze? Such a poor choice 

Waze is part of Google now. And they're entering into partnerships with state governments to supply traffic information to one another. I was "invited" to a meeting in Frankfort last month at which this was discussed. The discussion was so in the weeds that it was a total waste of time.

[jwolfer]

{{omit for emphasis}}

Those of us on here are a minority in the fact that we could navigate without GPS. I use GPS/ google maps/Waze to check on traffic. And for fun see how long it takes GPS to recalculate when going off "approved " route.

The definitely default to interstates

Why Waze? Such a poor choice 

I don't like the Waze maps.  I like the warnings from other drivers about police etc. Sort of like a cyber CB

[SSOWorld]

That I can understand.