The south-west zonal commander of TRACE, Adekunle Ajibade, gave the warning while speaking in Ota.
Mr Ajibade said the accident which involved a truck and motorcycle, occurred at about 1.00p.m on Friday.
The corpses of victims have been deposited at the Ifo General Hospital, Ogun, while the survivors are also receiving treatment.
Mr Ajibade said that the vehicles had been towed off the expressway to ease the free flow of traffic in the area.
A cement truck with no registration number, heading to the tollgate from Sango-Ota, had a brake failure and rammed into four vehicles.
Mr Ajibade explained that the meeting was necessary to facilitate further engagements with key stakeholders.
Mr Ajibade explained that six persons —- four males, one female and a toddler —- were involved in the accident.
The South-West zonal commander expressed worry over incessant cases of road crashes involving motorcyclists on the road.
He said that the bus was coming from Sango-Ota heading towards Toll-gate.
Mr Ajibade cautioned motorists, especially truck drivers, against speeding.
