NEW YORK – On Sept. 14, Segway — famous for its Segway Personal Transporter scooters — announced a recall of all 23,500 machines it has sold to date, according to the Web site

The Bedford, N.H.-based company stated it is offering its customers, including more than 150 police departments around the world, a free software upgrade that will fix the problem. The U.S. Consumer Product Safety Commission has asked consumers to stop using the vehicles with immediate effect.

Segway is cooperating and has announced a voluntary recall due to a software flaw that has been known to cause the scooters’ wheels to instantly reverse direction and potentially injure riders.