I keep a full, printed road atlas in my vehicle, along with a few foldable, laminated maps of places I visit often. I’ve found the latter to be particularly useful for places where cell phone based GPS is not reliable, e.g., remote, rural places and…Boston. 
(edit: fixed typo)
lol at Boston! I also carry paper maps in the car. I usually travel to rural areas and the state map is fantastic for an overview. Plus there’s usually neat tidbits printed on the maps. :) Phone GPS to get me around.
I do keep a copy of Maps.me on my iPhone for when I am offline due to visiting, well yes… Boston. It offers a full free set of downloadable OpenStreetMaps maps. Great in a pinch.
Both Apple Maps and Google Maps allow you to download maps to be stored (and updated) on your device. I have one on my iPhone and iPad for my metro area (to cover dead cellular dead spots, including the carport of my apartment building. When I travel out of the area, I also load maps for the places I’m traveling to and the route to them.
Both apps allow you to manage the downloads from the account icon in the app.
Indeed they do, Alan. I do that as well, but I have the entire island of Ireland fully downloaded in Maps.me and it provides a backup to be sure, to be sure, to be sure…
Why am I not surprised? I live in the Boston suburbs within easy walking distance of the junction of route 128/95 and the MassTurnpike (I-90) and we have had people ring the doorbell telling us they were looking for somebody else’s house on GPS.
When I’m a planning a trip I usually look at Google Maps on my 27-inch desktop screen to plan the route. I prefer Google because it shows traffic, and when you like in the Boston area, traffic is can be an important consideration. If I’m going someplace new, I may print out copies of key areas either as a PDF or paper. (The color on my MacBookAir screen 2017 is rather faded, and a disappointment to me.) I enjoy using maps; working out routes and following them is a good mental exercise.
I’ll look for you the next time I’m there!
It really does seem to me that common GPS systems perform MUCH worse in the Boston area than in any other US city I visit frequently. Whether using an iPhone or a Garmin device, the GPS often will indicate I am blocks away from where I actually am, even when I’m not in the tunnel or when I’m in relatively open areas away from the city center. I do see similar behavior now and then in New York City, but it seems to be much less of an issue there.
Most of Manhattan is on a grid, but not much of the Boston area is. I don’t know how GPS works, but I’ll bet it relies to some extent on urban layouts.
Interesting thought. I haven’t noticed issues in the older parts of NYC, many of which are as jumbled and non-gridded as much of Boston. AFAIK, GPS is mostly about line of sight to satellites, having sufficient repeaters where line of sight is not great, and an absence of interfering signals. I think NYC has invested a lot into building an extensive repeater network, especially given the skyscraper density in some areas.
My GPS experience with Boston is bad enough often enough that I am willing to entertain conspiracy theories about secret government organizations blocking GPS and also perhaps some extraterrestrial shenanigans.
In my experience, Google Maps is not useful for details. Google has a minimum area that can be downloaded, and zooming in using the the downloaded map doesn’t show much. For example, I might be interested in a neighborhood, but Google Maps makes me download the entire city, and then omits details for every neighborhood. If you have better luck, I wish I knew how you did it.
I have used Find My to try to locate a traveling companion who is sharing location information with me. This has always been a failure, showing locations (as you say) blocks away from actual locations, even if we are standing next to each other.
One well-known problem is multipath effects, caused by signals bouncing off nearby structures or topography. According to Wikipedia, motion of cars can offset multipath effects, but I imagine traffic jams would bring multipath effects back.
Celular networks can be quite vulnerable to interference from buildings and topography. It’s painfully obvious sometimes if someone calls my cell phone when I’m at home, where we have a large hill several hundred feet to the south that seems to block the signal.
I can get details by taking screen shots of Google maps on my Mac. You do lose the larger context, but can be helpful if you know in advance that you’re going to need certain details.
Speaking of line-of-sight, I’ve even had a difficult time initiating Maps in downtown Hartford due to the buildings. My general rule now is to just stay out of cities 
As I have mentioned in a related discussion, in Australia I use a navigation app - Metroview - that has all of Australia mapped in about 1Gb. This is possible, I guess, because Australia is large but mostly unpopulated so there are relatively few roads to be mapped. So it only needs a GPS signal - no internet connection.
Metroview has a small annual subscription for traffic info that is useful when there is internet connection.
Its big advantage is the Speedalert function that alerts me if I exceed the speed limit (I have mine set to 3km/h which enables me to easily drive within the speed limit without excessive alerts). I have conducted road safety research in this field and was pleased to be involved in early development of speed assist systems.
Anyway, back on topic (sort of), it seems that Apple and Google have difficulty with reliable speed limit mapping and so they are reluctant to add a speed alert feature to their navigator apps. However I understand that Google Maps has the feature in some countries. Reliable speed limit information is, of course, essential for self-driving cars.
Which I find really interesting, considering that Waze (owned by Google, but kept mostly separate from Google Maps) has had this feature for years. The only real difference I see in their ability to map speed limits is that Waze was designed from the ground up to crowdsource its information from users and so is much more responsive to changes reported by those users. Map issues reported to Google and Apple have to go through “process”, whereas those reported to Waze are addressed directly by its army of volunteer mappers.
I’ve found Waze’s speed limit information to be fairly accurate in general. It lags when a speed limit on a particular stretch of road gets changed, but not for long. Temporary speed limit reductions for construction seem to give it the most trouble, which is understandable considering that many construction restrictions are ad hoc to one or two days, so they’re often already gone by the time a map editor gets a chance to review and verify them.
My main issue is the next step after accurate speed limit mapping - that is the option to have speed alerts if the vehicle exceeds the speed limit by a selected amount.
European regulations now require new vehicles to have these speed assist systems (admittedly with teething issues) but there is huge road safety potential for smart phones to provide advisory speed alerts for existing/older vehicles.
Research that I have contributed to indicates that around 15% of fatal/serious injuries in the USA would have been avoided if an involved vehicle had not been low range speeding (1 to 10km/h over the speed limit).
Waze provides exactly that, at least in the US. With the option turned on, if my speed exceeds the posted limit by a user-set amount (I use 5 over the limit), the speed indicator on the screen turns red and briefly flashes larger, and it emits an alert tone if I’ve enabled it. I’ve been using this feature for years.
Additional coverage of GPS complaints about Boston
https://www.axios.com/local/boston/2025/04/14/carplay-android-auto-dead-zones-wifi-interference
Paper maps were helpful, but invariably out of date for some areas.
I’ve never encountered any major problems with Google Maps, but have had Apple Maps choose completely ridiculous convoluted routes.
I did try using the speed alerting option in navigators in the early days, but it is a pointless feature for travelling anywhere that I already know the speed standards. My car has the necessary speed indicating device right in front of me and I can just add on a percentage to estimate my real road speed. The navigator alert could come in handy in another country without any posted limits if it alerts quickly enough to avoid whatever may be the local favoured revenue gathering sites.