Work by SP Energy Networks is taking place on Scotland Street, the main A495 Oswestry to Whitchurch Road which goes through the town.
The energy company says the closure is necessary for emergency utility works.
Through traffic is instead using an already busy residential street, Cambria Avenue.
The traffic, including heavy goods vehicles and buses has been at a standstill many times with gridlock throughout Ellesmere.
Hold-ups have been aggravated by school traffic, taking children to both Ellesmere Primary and the Lakelands Secondary School - and temporary traffic lights for Severn Trent roadworks on Cambrian Avenue itself.
On Tuesday resident posted photos of the problems, They took to social media saying the roadworks should have taken place over the Christmas holidays when children were not at school.
Some said they had been trapped in their own driveways by the constant traffic jam and had suffered abuse from motorists trying to get their own vehicles out.
Lakeside Coaches bus company said: "The 449 Oswestry Service and 208 Ellesmere Town Service will experience delays and rerouting as best we can, please be patient we will try our very best."
Ellesmere resident Bob McBride said: "It is a genuine hazard at school time you would not fit an ambulance in anywhere ,it was gridlock. It is a chaotic situation that could have been managed better."
The Scotland Street closure is due to be completed by midnight on January 13, while the three way traffic control in Cambria Avenue for Severn Trent Water roadworks is due to last until 4pm on Wednesday .