There's one lane closed between Junction 16 (A3102 / B4005 Swindon West) and Junction 17 (A350 / A429 / B4122 Chippenham) due to a broken down lorry.
More top news
Sunday has the best of the weather this weekend, looking fine and sunny with high temperatures. Some showers around on Saturday.
Police have this afternoon confirmed they have arrested two people in connection with a shooting in Somerset last night
More than 2,000 young people are gathering on Dartmoor today ready to take part in the Ten Tors challenge.