Vivien Ayling was driving to work along the A27 when she says the jet crashed on the road beside her. She told BBC Radio 5 Live: "I saw this plane coming towards me and I thought 'Gosh, he's really low, is that allowed?'
"And then all of a sudden he got lower and I thought 'He's going to come straight into me' and then he veered off to my right and he just smacked straight on to the opposite carriageway to me, and then there was this massive great fireball and smoke went up."
The aftermath was "like a bomb exploding", she said, adding: "I decided to drive on through it - it fortunately went over my head.
"I stopped, looked back and thought there's going to be another explosion with all this aviation fuel around so I thought what do I do? So I thought best get out of there.
"You don't know what you'd do in that situation. I did what I felt was right in a split second."
She believes pilot Andy Hill was trying to avoid the road: "He obviously was trying to get to the field rather to land on them, on the road. That's probably why he veered off and didn't end up in my carriageway."
Dave Hampton was at the air show with his family.
"We were behind the marquee at the time, having a picnic and we had literally turned up 10 minutes before," he said.
"We saw the Hawker Hunter fly over the marquee, we saw it fly up, then we saw it almost turn around to come back.
"Our two boys who are very passionate about planes asked where the plane was and we said it would be along in a minute when we heard what sounded like a sonic boom - it sounded like the plane had broken the sound barrier.
"People around us then started standing up and saying 'Oh my God, it's come down' and at that time we looked over and we saw the big plume of smoke coming over the marquee."
Gairo Gomez, who works at the nearby Ricardo Technological Centre, said the whole building shook.
"I saw the plane going down. I heard a huge bang and the glass was shaking and the doors were banging, the whole building was shaking.
"I saw some smoke later on, but at the time I didn't realise what had happened."
Archie Tipple was a spectator at the event.
"We were stood on a footbridge by the Red Lion Inn, about 300m from the A27.
"I was photographing the aircraft as it started its display and as it climbed and climbed and climbed I thought, this is pretty good.
"But he was coming in a little bit low and I was still photographing it as it came down and then all of a sudden you just knew what was coming.
"It just immediately changed the atmosphere, from a festive one to something quite sombre," he said.
Nicholas Hair described the aftermath at the airfield.
"Strangely enough the first thing that happened was silence.
"I've never seen so many grown men cry in my life. But people of all ages and genders were crying, screaming and then again just silence that just stayed over the field for 10, 15, 20 minutes."
'
Jane Groves, from Shoreham, witnessed the plane crashing after her car broke down on the A27.
"My husband and I had stopped between the slip roads going to and from Shoreham. We got out, put on the hazards and phoned Green Flag.
"We were 400 yards from where the plane crashed. The passing cars were going so slow in the traffic and people were asking us if we needed water, feeling sorry for us - they had no idea what they were driving into.
"I saw a wedding car and thought to myself 'He is having a bad day, I hope he gets to the bride on time' and then five minutes later, I watched the plane crash into the traffic.
"We stood in the road diverting the traffic down the slip road until the emergency services came. If it wasn't for that, the ambulances wouldn't have been able to get through.
"This will stay with me forever."
Ailish Southall was driving along the A27 with her two children when the plane crashed close to them.
"There were huge amounts of fire and we ran from the car to kind of avoid the debris."
Lee Allwright, who was also close, said:  "It was extremely hot. You could hear the plane as it took out the traffic lights on the road.  You could hear the scraping.
"People didn't know what to do."
Ian Whitney was standing on the grass verge opposite to where the plane crashed.
"We saw the whole thing. We were watching it as the plane looped and I said 'he isn't going to make that!' It just plunged straight into the cars.
"There was the most awful thud followed by a ball of flame coming down the road at us. We had to run to avoid the debris and the intense heat.
"Everyone ran in different directions. Then there was an eerie silence of disbelief, before lots of people started crying."
Matt England from the South East Coast Ambulance Service was at the crash scene.
"We had obviously a very challenging scene over roughly a kilometre to deal with and we sent six ambulances, a hazardous area response team, two other response cars, four officers and two aircraft from our air ambulance charity to the incident," he said.
"We did take one person who was very severely injured to the Royal Sussex County Hospital by air ambulance straight away and then the lesser injured were dealt with at the scene initially and then taken to other hospitals."
Eyewitnesses have described the scene as a vintage jet crashed while performing at an air show in West Sussex.