When you're adding a grid of ways (such as the parking aisles you added to the La Grande Wallmart), make sure there's an intersection (a grey dot) at each point where they cross. Computers are, as I noted, rather literal-minded, and they'll have you driving around in spirals trying to get out of the parking lot otherwise.

When you need to change the attributes of part of a road, don't draw another road over the original like you've done here. Computers are rather literal-minded, and they'll treat it as a bridge, or an embankment, or whatever, stacked on top of another road.

The correct way to do this is to split the road into two or three pieces, and then make the changes to the appropriate part:
1) Click on the road to highlight it.
2) If there isn't already a node (a white circle) in the correct place, click on a nearby white triangle and drag it to create one.
3) Right-click on the node and select "split" (the scissors icon) to split the road in two at that point.
4) Repeat if needed to get a third piece.
5) Click on the part of the road you want to change and change it.

Welcome to OpenStreetMap! I've got some questions about the changes you've made, as well as some tips for better editing.

1. Are you sure the stream you added as "Sanderson Creek" is called that? The USGS topo map has it as "Mill Creek".

2. Is thre a reason why you re-tagged a stretch of demolished railway through Post Falls from "razed" to "abandoned"? "Abandoned" should only be used when there's still evidence of the track, such as the gravel railbed.

3. There's an easy way to make square-cornered buildings: once you've drawn and tagged the building, highlight it and hit the "s" key or right-click and select "square" from the menu. This even works (usually) for 45-degree angles.

4. "Ruins" is only intended for things of historic interest. For things that have simply been demolished or fallen out of use, the "lifecycle prefix" tagging system is prefered: osm.wiki/Lifecycle_prefix

5. Have you considered editing in smaller pieces at a time? Editing in large chunks like this makes your edits show up in the history for most of Washington and Oregon, and makes it hard to ask you about just one aspect of your work at a time.

"Living street" is pretty much purely a European thing. In the US, anything that seems to match the description of a "living street" should be tagged as either a driveway or a residential road.

Please don't attach areas such as parks or landuses to roads. Sure, it makes the map look a little nicer at extreme zoom levels, but it also makes it much harder to adjust the area or the road in the future.

I've reverted this: the original version was correct. The western section of the Marina Drive link is two-way, to provide access to the parking lots to the north of the road.

A couple of tips for making better-looking building outlines:

First, it's easier to trace the actual building if you zoom in quite a ways.

And second, once you've got the basic outline done, you can square up the corners by selecting the building and hitting the "S" key.

Are you sure the location and/or address for "Good Deeds Mortgage" is correct? "State Street" looks like it's a block away.

When you say this is "for assignment", do you mean that someone gave you the task of deliberately adding false data to the map?

Did you not notice that "sensor garage door repair" is a) glued to the middle of a road, b) misplaced (the "401" addresses are about a half-block to the west), and c) probably spam?

If you're going to be correcting errors, please check for other mistakes while you're at it.

The correct way to deal with a private drive isn't to delete it, but to mark it as "private" -- which is exactly what Leif Nelson did four years ago.

In case you haven't already noticed, in Spokane County, the "Esri World Imagery" option is far sharper than Bing imagery, and nearly as new. It's good enough to let you tell adjacent buildings apart, distinguish garden sheds from parked travel trailers, or map the individual shingles on a roof.

Is there a reason why you consider Hoerner/Colton/Jay to be tertiary roads? They didn't feel very arterial-like the last time I drove through, and they're lacking most of the usual indications, such as an elevated speed limit. (Jay is also lacking lane markings.)

Could you do your updates in smaller pieces? It's hard to check for possible mistakes when a changeset is scattered across half a continent.

Something about how you're editing is occasionally creating duplicate objects. This edit duplicated the bicycle parking and other objects around Conflux Brewing, and a previous one doubled up some of the roads and amenities of a campground.

I've cleaned them up, but it's something to watch out for in the future.

I'm not sure what you were trying to do here, but you've tagged some sections of rail with the tags "Lincoln=County" and "Port=Authority".

There's an existing marker for a "Walla Walla Baking Company" at this location. Are the two the same business?

Best practice is to spell out road names in full. It's easy for a computer to abbreviate a name if it needs to save space, but it's considerably harder to automatically expand abbreviations. "N" for "North" isn't too bad, but does "St" mean "Street", "State", or "Saint"?

Vandalism is something that everyone should understand. It is wrong to delete a school from the map in order to promote your business.

This is officially a *right of way*, which is not the same thing as a street. It's got a line of boulders across it near the Rosamond, and the stretch past the boulders is heavily decayed, with grass growing in the cracks, and decades of dirt and pine needles covering sections of it.

Unbuilt or abandoned right-of-ways are common in the city's larger parks: Manito, Palisades, High Bridge, and Finch Arboretum all have them. Riverfront Park has the opposite situation: Washington, Stevens, and Post are all built on park property, not public right-of-ways.

It's pretty clear that this *was* the south end of Woodland before I-90 was built, but it was abandoned as part of the freeway construction, probably in the early 1960s. If it's still on the city's map, it's because nobody's bothered to fill out the paperwork for removing it.