REVERE – Police officers shut down a state water-valve repair job on Fenno Street last Friday, but state officials vowed that action and similar shut downs across the state will not keep them from implementing a plan to replace police road details with state-hired flaggers.State transportation officials claim they can save $5.7 million to $7.2 million under new state regulations that call for replacing police with flaggers on select public works projects.Flagger plan opponents, including Revere Capt. James Guido and Chief Terence Reardon, claim the cost of flaggers is likely to match the cost of hiring police details with less protection for the public.Hourly rates collectively negotiated for police officers working private utility details range from $35 to $42 on the North Shore with Revere officers being paid $37 an hour.The state prevailing wage for flaggers and signalers in metropolitan Boston is slated to increase from $36.95 an hour to $37.45 an hour on May 31.Several Revere officers earned over $40,000 in detail pay alone, not counting their base salary, in 2007. But utilities hiring details also pay a fee to the city that totaled $100,000 last year.Officers argue that local police are more familiar with local road conditions than hired flag wavers and, because they are armed and in uniform, provide added protection on local streets.”If the pay is similar to a police officer, it is much better having a police officer,” Guido said.State transportation officials started assigning flaggers to road jobs Tuesday morning, with the changeover functioning smoothly at four sites but greeted by a police picket in Woburn.The first wave of civilian flaggers will be supplemented within the next two weeks by trained and certified flaggers at roughly 20 sites, state officials said.Guido said police shut down the Fenno Street job because the Massachusetts Water Resources Authority work crew filed “a last minute” traffic safety plan that failed to meet parking needs or accommodate traffic in both directions on Fenno.He said the new state road job regulations call for anyone doing road repairs to provide local police with a traffic safety plan and start work only after the plan is approved.MWRA spokeswoman Ria Convery said the Fenno Street work involved routine maintenance and its delay did not interrupt water service to residents.”We’ll hang back a couple of days and see how this shakes out,” Convery said.The City Council passed an ordinance last month calling for repair work on local streets to be overseen by at least one Revere police officer.Mayor Thomas Ambrosino signed the ordinance but told councilors that details could become a discussion point in collective bargaining talks.Councilors are seeking random drug testing for local police and Ambrosino said the “consequent desire of the police unions to include protective language for police details within their respective collective bargaining agreements may provide an opening for securing this drug testing concession.”