The Garmin Edge 530/830/1030 can be loaded up with extensive map data, and can give you live routing, even without a cellular connection.
Wahoo's ELEMNT ROAM can also do routing on the fly.
The Sigma Rox 12 also has extensive navigation functions.
There are some smartphone apps that can do this—I think the best-known are Ride with GPS ...
My guess is that "popularity routing" is weighted quite heavily in the choice of route, and "minimise time" is a secondary weighting.
I see Google has routed you on the A541, which is definitely more direct, but may be less "compatible" with cyclists and therefore less popular. The Strava route has used B5429 which is even ...
I highly recommend https://brouter.de/brouter-web for bicycle route planning. It also calculates elevation gain/loss and tries to avoid elevation changes.
Keep in mind that elevation data can be inaccurate since it’s usually using Digital Elevation Models which are based on satellite data. For example it might miss things like bridges entirely and display a ...
For those still interested, there's a pretty solid map site available now covering the US. Not everything is on there, and you can add more gravel roads as you find them.
Allows you to draw no-go areas.
Allows you to specify cost for ascents or descents. I’m not sure it’s possible to tell it to completely avoid streets above a certain incline. You could set the cost very high and set the cutoff to whatever you like. Disadvantage of this approach is that inclines below the cutoff are not ...
Point 1, hearing the outside world, is mostly easy. If the audio is too-high a volume it can still drown out the background, but that's got to be quite loud.
Point 2, these headphones have to work with your device. If that means bluetooth, then battery life becomes a consideration. If your device has audio-output jack then that's another option.
Do note -...
Some routing algorithms really don't like UK A or even B roads, and will do silly things to try to avoid them. A short stretch of dual carriageway to allow overtaking is another potential feature for the algorithm to avoid. Many services use openstreetmap data, and tags there can be wrong, so it's possible there are one or two places the Garmin doesn't think ...
The Garmin Monterra can do that (and android-based Garmin GPS). I say 'can' because apparently it is still for sale, but i am not sure i would actually recommend someone else to buy it.
You load an OpenStreetMap of the area, then the routes can change offline, and also depending on which mode you choose (walking, bike, road,..)
If you're up for a phone app, I've been using Navmii to do this recently.
It uses OpenStreetMap mapping and calculates its routes in the phone, not on some server. So it works offline. The maps include cycle paths and bridleways.
It carries some adverts but there's an option to pay to turn them off.
I've not been using it long enough to give a detailed ...
It's possible to get an estimate (rough, but quite possibly better than Google's) using Strava route builder in manual mode. I've checked against a local motorway (where cycling is illegal and would be very dangerous) and figures are not unreasonable. You'll need a (free) login. What you need to do:
without enabling manual mode, click on your start point