PS The CyclOSM layer on OSM website or at https://www.cyclosm.org/#map=14/53.2737/-6.2206/cyclosm are a handy way to see the cycle infrastructure that has been mapped.

Hi, welcome to OSM!

Many of the cycle lanes you added were already mapped using the cycleway tag on the road.

There are two current approaches to mapping cycle paths: osm.wiki/Key:cycleway and osm.wiki/Tag:highway%3Dcycleway
Please read those pages to understand their intended use, and pros/cons of each approach. Obviously choose whichever approach you feel is best for the situation at hand, but understand the meaning of each, and also that applying both approaches, like has inadvertently happened here results in duplication.

Also, many of the cycle lane/track lines you've drawn (e.g. osm.org/way/1372763000) aren't continuous cycle lane/tracks in reality - there is actually no cycle lane at all for part of Sandyford Road.
The cycleway tags already added to the road reflects this intermittent and varying nature of the cycle lane/track, e.g osm.org/way/108345245

It's unfortunate that the iD editor doesn't give a visual indication of cycleway presence on a road with cycleway tags on it. I made the exact same mistake when I first contributed to OSM.

I hope this all makes sense!

Re. your fixme. It is effectively one-way due to how narrow it is, and due to the turn restrictions at the western junction which prevent traffic from entering it at that end.
However, there are no road markings or signs to stop someone from driving westwards on this section of road, then parking at the side of the road and later heading back eastbound.
So in theory it is a two-way street, but it's practically one-way.

This seems to have resulted in stray house tags being added to nodes, in addition to areas (e.g. at the corners of a house).

Also FYI the wiki page for mapping houses recommends "house=semi-detached" or "building=semidetached_house", but I don't see any mention of "house=semi_detached". I could be out of the loop, I'm assuming the wiki is up to date on this.
osm.wiki/Key:house

Ok, in that case I wouldn't tag as highway=construction because navigation software will treat the road as closed and unusable. You could map the affected road as being one-way alternating, and map a separate footpath with highway=construction. However you should consider how long the works are going to last. I read somewhere that road works that will last less than 3 months should not be mapped, and started doing same. I don't think there's a hard rule around this, but the main factor for me is that some navigation apps might not update their OSM data for months, which can have the effect of the app avoiding a road that has since re-opened. In this case since its basically a layout change and not a closure, there will probably be little/no impact on routing choices for navigation apps so it's probably OK to map it here IMO.

Hey, sorry for not contacting you about this. I assumed the road is still open to two-way traffic as I saw some housing estates that are only reachable via that road. Is the road completely blocked?

Thanks!

This looks like the wrong location to add this park. Please re-check.