The MotoGP riders' safety commission will review the proximity of walls to the track at Motegi on Friday after both Alex de Angelis and Pol Espargaro suffered frightening falls during the Japanese Grand Prix weekend.

De Angelis remains in intensive care in Dokkyo University hospital after colliding with a barrier in FP4 while the younger Espargaro brother was extremely fortunate to walk away uninjured having impacted a track-side wall at over 200kph.

On Thursday at Phillip Island several riders including Espargaro, Valentino Rossi and Andrea Dovizioso said they would address this issue in the safety commission meeting that is scheduled for Friday.

"Always we need more run off," said Espargaro. "As much as possible. But there is no space. There we have to speak in the safety commission because my crash and Alex's crash we both hit the walls. They were not normal crashes but we hit the walls because it was possible. We had to ask the questions and speak about Motegi to try and improve it."

Explaining the crash that came just over a lap from the chequered flag, the former Moto2 world champion said, "The front and the rear tyre were worn, especially the front, which was really wasted. It was not the correct tyre for this type of race. We did not have the opportunity to choose the harder one.

"At the beginning of the race I began to feel some movement. In the middle it was crazy and by the end I crashed on the straightaway. I was just braking straight and I locked the front from a lot of metres. I just crashed and it was not really lucky because I was going out to brake. Going out put me on the wall.

"I hit the wall with the helmet. I'm well protected. It had to be more than 250kph for sure. In that straight where I was going 290 more or less. I started to brake a little bit plus the crash."

It was later confirmed by the Tech3 team that he fell at 240kph. Dovizioso meanwhile stated the effectiveness of trackside airfences needs to be evaluated, having explained that they do not work best when impacted from an acute angle.

"It is very difficult here with the airfence," he said during the pre-race press conference. "They explain to us that it works if you hit the air fence like this (makes head-on motion with hands) but if you hit it like this (from a slight angle) they say it's worse. It's very difficult to make it safer. We will speak about that.

"Even like that we will try to improve what we can but it is very difficult. For us it's impossible to have a completely safe track. We need four times the space that we have now to have that. We need more to speak every weekend and we need to improve this situation because the margin is small.

"Where de Angelis crash there are a lot of areas like this in every track. Unfortunately there is no possibility to have everywhere 100 percent. I think in the safety commission we work a lot and we try to get the feedback from the riders inside the track to understand where to improve where they can. Unfortunately for our sport it's impossible to have a completely safe track."

Like his fellow Italian, Rossi acknowledged both incidents in Motegi were bizarre in as much as they came at spots that are not entirely normal places to crash. Such is the nature of MotoGP machines that protection is needed in both the outside and inside of the track.

"Tomorrow we will speak in the safety commission because Alex crash in one place that is very difficult to expect one hard crash. He go on the inside of the exit of one corner. Usually we concentrate on the outside," explained the championship leader. "With this type of bike and this amount of power it's difficult to understand where the bike wants to go.

"We will speak tomorrow because for sure the wall is very close to the track. Also where Pol crash was very dangerous. In a normal way Motegi is quite safe but it has some points that can be quite dangerous, like in the case of Espargaro and de Angelis."