BILLINGS After nearly a week of snow removal, some Billings residents remain frustrated with delays in clearing residential streets. In other Montana cities, the challenges are similar, and limited resources, high costs, and varying snowplowing methods are obstacles. It can be unpleasant to drive on unplowed streets, a big reason why the City of Billings has plow crews working around the clock. Residential plowing began on Sunday. On Friday, zones four and five, covering south Billings and downtown, were near completion, while plowing in zone six covering the Heights is expected to start later in the day. Takes us maybe roughly 10 days to get at most to get through. It just depends on the snow, how much snow we get, how it's sticking to the road. If it's ice, it's going slower. If it's slush, it peels off a lot faster," said Derick Miller, the city's Street Traffic Division manager.The wait for some in Billings has been frustrating, but the time can be due to high operating costs, fluctuating weather conditions, and a rising population. Across the state, the reasons for delays are similar.   It would be great if I could plow the whole city in a day or 24 hours or 48 hours, but that would take a massive uptick in the resources, a quadruple or 10 times more people and plows that I have. That's not practical nor affordable," said Brian Hensel, City of Missoula Deputy Public Works director for Streets Operation and Mobility. In Missoula, the plowing process is similar to Billings. Plowing begins after two inches of accumulation hit the ground, and they first plow priority streets, such as main and arterial routes. Then, residential areas are broken up and tackled by five city pickup plows. According to Hensel, it can take up to one or two weeks to remove snow throughout the city. Forty percent of our streets are the local street category. The other 60 percent are priority, so those five pickup plows are responsible for 40 percent of the streets," said Hensel. In Billings, residential streets are contracted out to a private company, K2 Civil Inc. Missoula does not contract out its plowing for residential. Hensel said the city looked at hiring private contractors in 2019 instead of budgeting for pickups but had difficulty finding workers. So the decision was made, 'Let's just spend money on the pickups and the plows and the additional employees,' said Hensel. I could (contract) if we had a severe enough of event and I needed to hire some folks, I could, but typically we haven't. That's been partially assisted with the less severe winners that we've had.Snow removal can also be expensive. The City of Missoula usually spends $300,000 to $500,000 on liquid de-icer per winter. "Typically we will go over budget on liquid de-ice. Sand isn't that expensive. About 19 bucks a ton, said Hensel.  Other cities, such as Bozeman, Helena, and Great Falls, use similar, but unique, systems. Helena divides its city into eight zones, plowing priority streets first and moving into residential after. The process usually takes three to four days to complete. Great Falls plows all of its priority routes but does not plow residential streets unless necessary. All handle plowing operations with city crews for similar reasons of cost and the difficulty in finding those willing to take on the work.  There's so many different variables involved with snow operations that it's hard to get a fair comparison apples to apples," said Hensel.  Regardless of each city's approach, the demands of winter snow removal are not easy, and it takes time to get the job done properly. Whether its using city crews or private contractors, plowing remains challenging and costly for each community."Everybody's got a different idea of how they do it. Their citizens are expectant of different things," said Miller. We just do what we feel is right, what the citizens want, as well as (other cities). They do the best that they can with the resources given."