How does Google maps update road changes?

Hello Everyone,

We live in a very small town in the middle of nowhere. Recently the county installed a roundabout at an intersection. Using Google Maps GPS I noticed that the roundabout had been updated in about a week. How does Google know about the change? Does the county notify them? I find it hard to believe that Google checks every rural road every day or so.

I’m guessing that ultimately (possibly several links down the chain), someone has to go to the county courthouse and look up the plats of the developments and road changes that were approved.

That doesn’t mean that Google has a guy who does that- they may contract with a company to get them say… all Texas updates annually or something.

The reason I think they go to the courthouse is because back in college, I worked summers for a civil engineering firm that primarily did water, sewer and drainage work for MUD districts, counties and small towns in our immediate area. Typically the land planners would design the actual housing developments, but we’d (technically I’d) schlep them to the county courthouse and register the surveyed plats, as well as get the engineering approvals for the actual road construction and piping designs, etc…

Houston, at the time, had something called “Key Maps”, which were the standard maps used by the city and county agencies for navigation, which meant that my dad, as part of the Water department, was issued an up to date Key Map every year. In about Christmas of 1994 or so, he brought his new map home, and I was looking through it, and spotted a development that we were still working on (I was working that Xmas break as well) and that I’d registered the previous summer.

It wasn’t actually built yet. It had been roughly surveyed and the plans had been registered with the county, but no roads actually existed. So someone from the map company had gone to the Ft. Bend courthouse and got the info for the development and put it on the map, despite it not being actually physically built yet.

Perhaps you’re not as far into the middle of nowhere as you believe and the Google people update data from your area fairly often… or maybe you simply got lucky and the recent construction coincided with when the Google crew routinely updated their photos and other data not caring if they caught every sidewalk curb replacement. I’m in a rural area less than 90 minutes away from a city of a million people, yet I can go on to Google maps right now and my property still appears as it did in 2009.

Well, has your property changed in a way that you would expect to show up on a map? E.g. had a road driven through it?

I don’t think the OP is saying that Google maps has a satellite photograph showing the roundabout; just that the map shows a roundabout at the junction concerned.

I can’t find it now on the new and “improved” version, but it used to be possible to report errors and changes to Google just by right-clicking on the map. I’ve done it a few times when roads were reconfigured, and once when I found a whole subdivision in the wrong place. It didn’t take much longer than a day or two for it to be changed.

I think Google relies on reporting more than satellite pictures or contractors. A few months ago a round about was closed for maintenance and they listed that the same day.

Not sure about Google, but with Waze I was able to report an error. Our private road was missing. It looked like I was driving along on a road, then suddenly was off-roading through a field.

I added our road, named it, there was a review, it was accepted, and I was thanked.

Most of it comes from people with Android phones, which (unless you opt out) automatically report data like this to Google.

Another example: My mother in law is building a house in a new estate. The roads have been laid down in the last few months and although there is no recent satellite/aerial photo of the development, the Google map shows the roads themselves. I assume town planners distribute information to map people on a regular basis. Mapping roads is hardly a new phenomenon after all.

Android phones and satellite photos are going to give you the general lay of the new roads, but the actual street names and addresses are going to have to come from the county or municipality.

Sure, but the OP’s example was an intersection being converted to a roundabout. That’s not something that would require any new names.

Work in a GIS department for County Gov. We have and create all of our own road/parcel maps. We use everything from Aerial photos that we contract to be flown or survey plats. Google/Map Quest etal has never asked us for any data.

Thanks. I’d thought the information would flow a bit more freely, but I guess there are many reasons why it doesn’t.

But it appears from the OP it does flow freely, since the new roundabout was featuring on Google maps within a week of construction. Presumably this was some months after planning/approval. It seems far more likely that Google got this data from the planning/approval process than from a survey made after construction.

Enipla’s county government may not be supplying data directly to Google maps or others, but they may be supplying it to some body or agency which aggregates such information from counties. And Google may be getting it from them.

Google maps, remember, covers not just the entire US but pretty much the entire world. It’s unlikely that Google liaises directly with the lowest level of local government in every country throughout the world. There’d be at least one, and quite possibly more than one, intermediate agency between Dibley Parish Council and Google. Nevertheless the relevant data does seem to show up on Google maps fairly quickly.

And if they did they would be stealing it.

We do sell it (a different thread, I don’t think we should charge for it). But it is licensed when we sell it. To the buyer. AFAIK, large scale mapping services do not use this data. And if they did, it would be against our license agreement.

Colorado is just starting to put together this data for emergency service issues for the State.

Fair enough. I am not going to accuse Google of stealing the data they employ to construct their maps.

But, my point is, they’re getting the data from somewhere. When a new roundabout in an out-of-the-way place turns up on Google maps within a week of construction, it defies common sense to suggest that it turns up because, during that week, Google had made a survey and updated their maps. Google couldn’t possibly keep their maps up to date in a useful way by constantly resurveying the entire globe.

So, even if I don’t know the exact mechanism, I’d be amazed to discover that the source of most updates to Google maps wasn’t the decisions and approvals of highway authorities, planning authorities, etc. They may not be supplied directly from the authorities to Google, but the data is making it’s way through. And in 99 cases out of a hundred, when a new roundabout appears on Google maps, it does so not because Google surveyors found it, but because Google was notified of a decision to construct a roundabout at that place.

There is a huge problem with putting together different datasets and their attributes. It’s being worked on. Google maps etal has the ability to look at the world as a whole, where local systems address local issues.

Map projections, local survey control, historical control that is long, long gone, odd terrain, wildly different data attributes are just the start.

Anywho, Google etal must use Sat aerial mapping and change detection software augmented by people on the ground to detect new roads and GPS them to fit their system.

Addresses can be estimated by the mile post, block system or what may be used in the area until it can be checked out.

There is a dozen ways to do this.

Now, it’s the “Send Feedback” item in the menu.

Keep in mind that even though the roundabout only opened recently, construction had been underway for months. The raw dirt of construction shows up really well in aerial photos, and is one of the ways mapmakers like myself spot new subdivisions and get them in place as soon as they’re driveable, or even before, for printed maps. The old issue of showing platted—but not yet built—“paper streets” is thankfully not the problem it used to be.

US metro areas are flown at least twice a year by Nearmaps. Even if they don’t put them up for public consumption, Google certainly can afford to use Nearmap imagery to compare against their previous imagery and have software bring to a human’s attention the possible alteration.

Besides that, you have crowdsourcing techniques like Waze and the Android GPS reports and the league of Open Street Map aficionados. Road geeks love to play their part in reporting and redrawing on OSM any change that motorists might notice. OSM is open data that Google can easily compare against; even county data that’s sold is only protectable as a database. Once the facts in that data are out there on the web, anyone can use them to update their maps.

Android is owned by Google, so basically it has access to all the android peripheral devices (tablets, smartphones,smart watches) so when you turn on GPS or location on your device, Google gets access to your location,speeds, now like you there would be various other individuals who would be using the same feature on their smartphones, preferably while travelling. So when Google detects that most of the devices on that particular route (road) are moving slow than their normal speed this means that there is traffic on that particular road. So they mark them in yellow, red likewise.
When some particular roads show no device passing by, Google checks whether some construction is going on at that site or not , if yes you’ll see a red line on Google maps.

Helen Greene
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