M4 Closure Within J8 Westbound, Berkshire, Friday 16 September 2016.

The M4 was closed west­bound within J8 due to exten­sive flood­ing fol­low­ing tor­ren­tial rain.


At approx­i­mately 04:50 our East Regional Con­trol Cen­tre was noti­fied of severe flood­ing on the west­bound entry slip road at J8 of the M4 in Berk­shire. CCTV showed that there was also excess flood water across lanes 1 and 2 on the main car­riage­way within the junc­tion. Traf­fic Offi­cers were imme­di­ately deployed to the scene and High­ways Eng­land con­trac­tors were alerted. At the same time, units from Royal Berk­shire Fire and Res­cue ser­vice were mobilised. Once on scene, it was clear that it would take some time to drain the sur­face water, and the deci­sion was made to close the entry slip, and both lanes 1 and 2 to allow the fire ser­vice to clear the water safely. Our national teams started to push this infor­ma­tion out to the media and via our Twit­ter chan­nels as well as set­ting vari­able mes­sage signs fur­ther afield to warn you of the incident.

The fire ser­vice arrived on scene at approx. 06.30 and began to pump the water at a rate of 3000 gal­lons per minute. While this was hap­pen­ing, sev­eral vehi­cles were reported to have bro­ken down in the flooded sec­tion, and these were removed by Thames Val­ley Police. By this point delays were start­ing to build, mainly due to the fact that this inci­dent was run­ning into the morn­ing peak traf­fic time.

At approx. 08.15, the fire ser­vice and High­ways Eng­land con­trac­tors had cleared the flood water from the entry slip road, and deemed it safe to re-open. This then allowed them to con­cen­trate on pump­ing the water from the main carriageway.

Our con­trac­tors on scene con­tin­ued to work hard to clear the flood water and lane 3 remained open past the scene allow­ing traf­fic to pass. How­ever, after re-assessing the sit­u­a­tion for safety rea­sons, the deci­sion was made to close the car­riage­way com­pletely within the junc­tion. Traf­fic was diverted up and over J8 via the exit and entry slip roads. Our teams in the National Traf­fic Oper­a­tions Cen­tre imme­di­ately set signs and sig­nals across the net­work to advise traf­fic head­ing in this direc­tion of the closure.

Due to the large vol­ume of water on the car­riage­way and the fact that it con­tin­ued to rain, the fire ser­vice sent a fur­ther 3 pumps to assist those already work­ing on scene to help clear the flood water.



Because the car­riage­way was now closed and traf­fic was being pushed off at J8, delays con­tin­ued to build and by early after­noon, con­ges­tion was back to J5. A break­ing news mes­sage was set on the High­ways Eng­land web­site to advise cus­tomers of the severe delays. Tweets were issued advis­ing cus­tomers to allow extra time for their jour­neys, and where pos­si­ble to con­sider alter­na­tive routes.

We con­tin­ued to work through the after­noon and at approx. 16.15 our East Regional Con­trol Cen­tre con­firms that all excess sur­face water had been cleared and the car­riage­way had fully re-opened.

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