Long topic ... I’ll try to make it short ...
When a Community decides an item must be built or asset must be purchased for the benefit of those who are paying for it, this is Commerce/Capitalism They are agreeing to do this for their own specific “betterment”. While they probably know there are those who will benefit that do NOT pay for it, they are willing to bear the cost of those “Free Riders”.
For instance ... people generally look at trucks as being a problem ... as “inconvenient” ... however, MOST of those people are “Free Riders” since the Trucks and Businesses are the REASON that roads exist at all ... COMMERCE Created Roads and Bridges and Super Highways AND ... Mostly PAID for them. The roads WERE NOT built so You could Go See Grandma ... were that the case, there would BE NO Roads. Snowplows are Commerce/Capitalism.
When SOME Aspect of a Community decides it should use Tax Money to support “Free Riders” instead of, or over, Commerce ... THAT is Socialism ...
For instance ... back to Roads ... in many instances Gated Communities and Developments are REQUIRED to build, maintain and plow Their Own Roads because they are NOT Commerce. However, if that small community falls on hard times and can no longer afford to plow its own roads ... frequently a Government Official will decide the Larger Community (Municipality) SHOULD Plow those roads ... to PAY Tax Monies for something that is NOT Legitimately something it should be used for.
Section 8 Housing, Rent Controls, WIC ... these are all forms of “Anti Commerce” expenditures of Tax Income (Commerce Produced Monies) ...
Whenever Tax Money (all money is produced by Commerce) is spent on something that IS NOT Commerce Oriented ... that may, in fact, be ANTI Commerce ... THAT is “Socialism”.
Police, Fire, EMS, Road and Bridge, Schools ... these are all PRO Commerce ... they allow the Community to function ... to Work.
Social Security (Insurance), MediCare (part of SSI), Unemployment (Insurance), Disability (Insurance) are often acted toward as though they were Charity though they are NOT ... They were PAID FOR (Commerce) by the recipients.
MedicAid, Welfare, Food Stamps, ... “Free Services” ... these are ALL things being provided to a “Free Rider” from Monies Created by Commerce ... these are Socialistic.

I read "socialist snow plow" and i imagine a guy sitting behind the wheel of his truck at 330 in the morning cussing every "snowflake" that landed on his "windshield" wondering when the "blizzard" would end.

"Is it socialism every time we are taxed and the government spends it?"

In my view, the more a system is paid for by taxes on those who use it, the less "socialist" it is.

Roads are often supported by gasoline taxes or by property taxes (depending on the State). Police and EMS are often supported by sales or property taxes levied by the city. In these cases, the individuals who use the road (drivers) or benefit from the road (property owners) have to pay for more of it. The individuals who live in the city (and use city services) have to pay more for them. Ideally, we don't all have equal shares; instead those who are going to use the system are taxed to support the system. These taxpayers are better able to hold the local government accountable.

Gas and property taxes for roads are not socialist because fundamentally, they're not wealth transfer strategies.

Note: The US constitution specifically authorizes the Federal government to establish "Post Offices and post Roads". At least some road building is authorized at the Federal level.

I too have questioned if the example you mentioned above is indeed socialism, or would fall under another category. I believe some of the same was around during the times of the founding fathers, and I rather doubt they would have referred to such as socialism...