16 overpasses, and then disaster

State Police said the driver's GPS indicates he took the Belt Parkway to the Southern State Parkway. Both are prohibited for buses.

The bus crash that injured all 43 passengers on board Sunday night occurred when a coach bus hit an overpass on the Southern State Parkway.

Investigators said the driver was using a noncommercial GPS, which appears to have put him on a route from the Belt Parkway to the Southern State Parkway as he tried to get to his destination, the Walt Whitman Shops in Huntington Station.

Commercial vehicles, school buses, tractor trailers and other tall vehicles are prohibited from driving on New York parkways because of overpasses that are lower than the standard bridge clearance. It has led to hundreds of bridge strikes through the years.

If the driver in Sunday’s accident took the suspected route, he would have passed under 16 overpasses with clearance warning signs ranging from 12 feet, 3 inches to 7 feet, 3 inches before striking the 17th overpass at Eagle Avenue, with a minimum clearance of 7 feet, 7 inches. The height of the bus is roughly 12 feet, according to the bus manufacturer.

State Police Maj. David Candelaria said that the bus would have been able to pass safely through the overpasses, “if you generally stay in the middle lane.”

The suspected bus route on Sunday night

Click on the yellow markers for details on the overpasses

No sensors on the route

While the suspected route had several warning signs about low overpasses, it did not have any of the sensors the state is installing to warn over-height vehicles.

The state began a program last year to install “over-height vehicle detectors” at 13 parkway entrances in Nassau and Suffolk counties. The $4.3 million project saw five detectors installed in 2017, with an additional eight scheduled for this spring, but the state did not give a completion date.

They join three detectors installed in 2014. Only five of those installed are operational.

None of the sensors — installed or planned — was on the route investigators believe the bus driver took. One nonoperational sensor is in the area where the crash occurred, at the eastbound Southern State ramp at Eagle Avenue in Lakeview, but because the driver was already on the parkway, it wouldn’t have affected the outcome.

Here are the approximate locations, based on the state descriptions, and Sunday’s accident site is marked with a red star.

Bridge sensors installed or planned

  • Installed in 2017
  • Scheduled for spring 2018
  • Installed in 2014

How the sensors work

When operational, detectors on ramps send a beam that is set at a specific clearance height for the area.

An over-height vehicle that drives through the sensor would trigger a warning message on the LED screen attached to the device.

A camera linked to the state Department of Transportation would also record the incident.