A.First, if you haven’t already, you should make it a policy that using the phone (either to make a call or text) while driving is prohibited — no exceptions.
Unless you have driver facing cameras, it may be difficult to police phone use, but there are tools that you should require drivers to use while they’re in their vehicles and driving.
For example, Apple’s Do Not Disturb While Driving feature — available on iPhone 6 and newer models — automatically directs calls to voicemail and sends a preprogrammed message in response to texts while driving. You could police the use of this feature by calling or texting the driver when you know he or she is en route to a customer appointment. If they answer, you will be able to take steps to correct the behavior as required by your safety policy.
More fundamentally, you and all of your company’s leaders and stakeholders need to create a safety culture that encourages your drivers to put the phone down while driving and concentrate on getting to appointments safely. This means no sales teleconferences while employees are heading to their first appointments or requirements that a call or a text from a supervisor must be answered immediately (this is where the Do Not Disturb features would be extremely effective).