After years of planning, Palo Alto is preparing to take a significant step toward alleviating the worsening parking shortages in its two main commercial districts on Monday night, when the City Council votes to approve design contracts for new garages in downtown and near California Avenue.

By moving ahead with the contracts in its final meeting of the year, the council looks to achieve some long-awaited progress on a few of its most pressing infrastructure priorities. One is a new public-safety building, which would be across the street from a new parking structure on Sherman Avenue. Another is a new downtown garage, which would go up on a city-owned parking lot at the intersection of Hamilton Avenue and Waverley Street.

The biggest contract that the council is set to approve is with the firm RossDrulisCusenbery Architecture, which has spent several years assessing the city's public-safety needs and drawing up plans for a new police headquarters. In December 2015, the council agreed that the new building should be go up on a what is now a parking lot on Sherman, between Birch and Ash streets, kitty-corner from Santa Clara County Superior Court building. Construction of the three-story headquarters would only begin after the city builds a garage on another parking lot, off of Birch and behind Antonio's Nut House.

The parking structure will add 160 new parking stalls to the site, for a total of 460 spaces, and also include retail space.

Both the public-safety building and the new garage near California Avenue are included in the Infrastructure Plan that the council approved in 2014. The police building in particular has been a high city priority for more than a decade, with several independent assessors and citizen committees concluding that the existing police headquarters at City Hall is too small and seismically weak. A citizen committee that the city established to review Palo Alto's infrastructure needs concluded in a 2011 report that the existing structure is "unsafe and vulnerable."

According to the city's request for proposals, the parking garage and the public-safety building are expected to take about three years to complete. Much of 2017 will be spent on design reviews and environmental analysis, work that officials hope to complete by the end of the year. Under the city's tentative timeline, completion of the parking garage is targeted for late summer 2018, while the public-safety building would be up in late spring 2021.

Yet there is at least one cause of major concern: Construction costs have been rapidly escalating since the council adopted the Infrastructure Plan. The plan pegs the cost for the public-safety building and the garage at $57.8 million and $10.3 million, respectively. But as the new report from Public Works points out, costs may go up both because of the changes in the construction market and because of changes in the project, most notably a recent decision by the council to add retail space to the new Birch Street garage.

Lalo Perez, the city's chief financial officer, told the council's Finance Committee the rising construction costs are driven in large part by the high number of projects currently being built in the area. The heavy demand and high competition for labor has pushed up costs, he said. City Manager James Keene put it succinctly: Time is money.

"Fast decision-making and execution on capital projects is really in our best interests because those costs are going up faster than our revenue stream," Keene said.

The new Birch Street garage is one of several actions that the city is now undertaking to address growing citizen unrest over inadequate parking. Next week, the Planning and Transportation Commission is set to discuss the new Residential Parking Permit Program for the Evergreen Park neighborhood, which is next to the California Avenue Business District. Once the program is in place, area employees will no longer get free all-day parking on residential streets.

The new Evergreen Park parking program would be modeled largely on the one that was recently implemented in downtown. Much like the downtown program, permits would be sold only to residents and area employees, with the number of permits for workers capped at 250. According to the city planning staff's presentation in October, Evergreen Park would be divided into two zones, with 125 employee permits made available for each zone.

Residents would get one free permit per household, with an option of buying up to three more for $50 per year. For an employees within the district, the permit would cost either $149 or $50 per year, depending on income level.

The new downtown garage, meanwhile, is expected to provide a fresh option for employees who can no longer rely on residential streets for all-day parking since where the downtown parking-permit program was launched. The plan calls for a garage that boosts the number of parking spaces on the corner lot from 86 to 300.

On Monday night, the council is expected to approve a $1.9 million contract with the firm Watry Designs to provide design and environmental-assessment services for the new structure. While the council has budgeted about $13 million for the downtown garage, staff plans to present an updated estimate during the preliminary design phase.

In the likely scenario that the costs for the two garages and the the public-safety building exceed expectations, the council will be able to tap into a $30 million contingency fund in the city's capital budget. The council can also draw up to $4.8 million for the downtown garage from the Downtown In-Lieu Parking Fund, according to Public Works.