HOV "Lanes"

Moderator: Unholy

Re: HOV "Lanes"

Postby sketch » Fri Aug 02, 2013 5:39 pm

kentsmith9 wrote:When being routed in the main lane and I am in the HOT lane, Waze updates my ETA live with earlier times in 1 minute increments (does not build up and suddenly change my ETA with a message). I assume this is altering the main lane timing for the non HOT/HOV drivers. Since Waze is able to assess I am in the HOV/HOT lane when I first start navigating, I would think it could ask me if I am in that alternate lane after being there for more than a few miles. I also assume that since Waze tracks actual vehicle paths even though it displays me in the main lane, it hopefully is not adding my faster time to the main lane average speed.

This will probably affect the "current traffic" speed, yes, but it shouldn't affect historical data, provided that the GPS traces are accurate enough. That's done with later analysis once your drives are uploaded.
sketch
Waze Global Champs
Waze Global Champs
 
Posts: 5852
Joined: Sat Aug 08, 2009 6:13 pm
Location: New Orleans, LA
Has thanked: 1389 times
Been thanked: 1882 times

Re: HOV "Lanes"

Postby kentsmith9 » Fri Aug 02, 2013 5:08 am

When I first joined we added the ~10 mile segment of I-680 S (Sunol to Milpitas) with an HOV/HOT lane. I drive it every day and have a Plug-in Prius so I can use it as a solo driver. The lane is not physically separated, but there is a double white line (illegal to cross) and various entrances and exits along the 10 miles.

I have played with the GPS sensitivity. Generally speaking with the way we have it mapped the freeway is wide enough in most areas to give about 2 lanes of separation. If I start my route before I am in the lane, Waze keeps me in the main lane while I cruise down the HOT lane (up here that lane is typically at the limit at all times). If I shut down Waze and restart it while I am in the lane, it usually shows me in the HOT lane and gives me the proper HOT exit points to get off the freeway.

When being routed in the main lane and I am in the HOT lane, Waze updates my ETA live with earlier times in 1 minute increments (does not build up and suddenly change my ETA with a message). I assume this is altering the main lane timing for the non HOT/HOV drivers. Since Waze is able to assess I am in the HOV/HOT lane when I first start navigating, I would think it could ask me if I am in that alternate lane after being there for more than a few miles. I also assume that since Waze tracks actual vehicle paths even though it displays me in the main lane, it hopefully is not adding my faster time to the main lane average speed.

If anyone takes a look at this segment of I-680 S note that I recently found out the way we set it up as a freeway lane is not what was proposed so we still have to update that.
kentsmith9
Waze Global Champs
Waze Global Champs
 
Posts: 5208
Joined: Mon Apr 23, 2012 3:33 pm
Location: SF/SJ Bay Area of Northern California
Has thanked: 1329 times
Been thanked: 1568 times

Re: HOV "Lanes"

Postby Daknife » Tue Jul 30, 2013 5:37 am

AndyPoms wrote:The lane guidance in other GPS units is done essentially by segment - it doesn't actually know what lane you are in, but information about the number lanes on the segment you are on.

Besides at a 95% confidence level, civilian GPS is only accurate to 7.8 meters (just over 25 feet)(1) - and minimum lane width in the US is 12 feet (2) so 25 feet covers two full lanes on either side.

Not entirely true, more devices available today are compliant with the WAAS system for which the above cited stats are the set minimum requirements to be considered compliant with the WAAS specification, but in testing by the NTSB it has proven to consistently provide an accuracy of 1m (3ft, 3 in) or less laterally, accurate enough even for GPS based flights and landings. Many older handset GPS's are not WAAS standard but more and more of the newer ones are are, and external receivers such as the Dual150 Bluetooth receiver are WAAS compliant. This standard is considered sufficiently accurate for aviation uses, as that was the primary reason for the creation of the WAAS system. And since Selective Availability was turned off by the DOD in 2000, even Just plain vanilla GPS measures to greater accuracy than the 7.8 meter minimum requirement for WAAS. Vanilla GPS measures at an accuracy of 2.5 meters. http://en.wikipedia.org/wiki/Wide_Area_Augmentation_System
Daknife
Waze Mentor
Waze Mentor
 
Posts: 1683
Joined: Sat Dec 24, 2011 11:03 pm
Location: Riverdale, Utah
Has thanked: 456 times
Been thanked: 228 times

Re: HOV "Lanes"

Postby bgodette » Tue Jul 30, 2013 4:30 am

Non separated HOV/HOT lanes should remain unmapped and left until we get some of the additional attributes from Google. This will include number of lanes and hopefully you can specify how many lanes are HOV/HOT. That combined with car profile in the client can separate out average speed data between HOV/HOT and regular lanes.

Or we wait 5 years for all our phones to have GPS chips that use the three (four?) major GPS systems at the same time for sub 1 meter accuracy. :ugeek:
bgodette
Waze Global Champs
Waze Global Champs
 
Posts: 3412
Joined: Wed Jul 06, 2011 8:19 pm
Location: Denver, CO
Has thanked: 108 times
Been thanked: 503 times

Re: HOV "Lanes"

Postby jemay » Mon Jul 29, 2013 4:06 pm

jemay wrote:The HOV wiki entry
...
I bring this up to help with the wiki understanding of what needs to be mapped for HOV lanes. The HOV wiki page should state that no HOV lanes should be mapped if it is a "free will" lane.


Wiki Page wrote:As an interim measure, these lanes should be added to the map as separate roads, with the road type as Parking Lot Roads. This means that if you are not currently in one of these lanes the routing will avoid it, but if you choose to get into the lane, the routing will work correctly.

I think something like this needs to be added.

... will work correctly. This should only be applied to dedicated lanes that have exit and entry points.
jemay
Waze Global Champs
Waze Global Champs
 
Posts: 1971
Joined: Tue Nov 09, 2010 1:26 am
Location: US South West - Lakewood, CA
Has thanked: 612 times
Been thanked: 896 times

Re: HOV "Lanes"

Postby CBenson » Mon Jul 29, 2013 3:55 pm

But given enough data, you don't have to every car plotted in the correct lane to extract some speed difference data from the lanes. I suppose volume discrepancies could overwhelm speed discrepancies. But I would not take the inability of consumer GPS receivers to place a car within a lane width to mean that plotting HOV lanes would be useless. Furthermore, if there is a significant speed difference say between 55-65 mph in the HOV lane and 35-45 in the regular lanes, then we can likely assume that clients that have self identified as HOV are in the HOV lanes. Thus, I continue to think that once a user can self identify as an HOV vehicle, then this topic should be revisited.
CBenson
Waze Global Champs
Waze Global Champs
 
Posts: 10330
Joined: Wed Nov 03, 2010 9:13 pm
Location: Crownsville, MD, US
Has thanked: 1069 times
Been thanked: 2355 times

Re: HOV "Lanes"

Postby russblau » Mon Jul 29, 2013 3:22 pm

I'm sure AndyPoms is right, but even without any stats, all you have to do is look at the GPS layer in the WME and you can see how wildly inaccurate some GPS readings are. If memory serves me right, I believe it takes 20-30 minutes of continuous operations for a GPS unit to reach full accuracy, too, so we are unlikely ever to approach "lane-level" accuracy for users with relatively short commutes.
russblau
State Manager
State Manager
 
Posts: 1188
Joined: Fri Oct 19, 2012 11:36 pm
Has thanked: 168 times
Been thanked: 489 times

Re: HOV "Lanes"

Postby AndyPoms » Mon Jul 29, 2013 11:16 am

The lane guidance in other GPS units is done essentially by segment - it doesn't actually know what lane you are in, but information about the number lanes on the segment you are on.

Besides at a 95% confidence level, civilian GPS is only accurate to 7.8 meters (just over 25 feet)(1) - and minimum lane width in the US is 12 feet (2) so 25 feet covers two full lanes on either side.
AndyPoms
Waze Global Champs
Waze Global Champs
 
Posts: 7150
Joined: Tue Dec 27, 2011 1:34 pm
Location: Hartford, CT
Has thanked: 128 times
Been thanked: 1312 times

Re: HOV "Lanes"

Postby CBenson » Mon Jul 29, 2013 10:25 am

And even if the resolution is low enough to place individual cars reliably in the HOV or regular, if the speeds are different, a speed diference should show in the aggregate data. I'm not mapping the HOV lanes either, but once we can indicate HOV status in the client, then I think this topic will need serious reconsideration.
CBenson
Waze Global Champs
Waze Global Champs
 
Posts: 10330
Joined: Wed Nov 03, 2010 9:13 pm
Location: Crownsville, MD, US
Has thanked: 1069 times
Been thanked: 2355 times

Re: HOV "Lanes"

Postby AndyPoms » Sat Jul 27, 2013 11:10 am

If it's just a lane and not a separate road, the GPS system (not Waze, but the actual GPS system) doesn't have the resolution to know which lane you are in, so it won't be able to tell if you are in the HOV lane or not.
AndyPoms
Waze Global Champs
Waze Global Champs
 
Posts: 7150
Joined: Tue Dec 27, 2011 1:34 pm
Location: Hartford, CT
Has thanked: 128 times
Been thanked: 1312 times

Next

Return to Wiki Updates and Discussion

Who is online

Users browsing this forum: Google Feedfetcher