[Talk-GB] We're missing changes to M1 Junction 36 which have apparently been in place for a year.

[Warin]

On 14/02/19 03:42, Ed Loach wrote:
> Paul wrote:
>
>> Jerry,
>>
>> No worries. I think I'll still pop down for a survey anyway because I now want to
>> try the GPS + car trick and see how it turns out. We'll compare changesets later :)
> Much of Clacton was originally mapped using that method, when there was no imagery covering the area.
> https://www.openstreetmap.org/user/EdLoach/traces/page/79
> When imagery and OS opendata became available it was usually pretty close. I was using (and still use) a Locosys GT-31.
>
> I have seen areas where the uploaded traces and the OSM roads seem to follow the pavement in the imagery and suspect it was mapped by a walker who hadn't adjusted for not walking down the middle of the road (I'm not talking a constant offset here as it depended which side of the roads they were walking).

Same applies for car traces. Best to average multiple trips in both directions.

>
> Accuracy will depend on the receiver and signal reception.

Yep. Multiple trips can help with everything but reception problems caused by local obstructions (buildings, cliffs etc.