Since January 2018, people who work at General Motors (GM) are not allowed to use their smartphones while walking.

That rule extends to employees with office jobs, as well as those in the company's factories. Here are four things we can learn from that approach.

1. A single behavior change has substantial effects

One of the noticeable effects of limiting smartphone use like GM has is that the rule encourages people to become more aware of what's going on around them. Jim Glynn, GM's Vice President of Global Workplace Safety, says the behavior change of not letting workers use smartphones as they walk makes them more in tune with their environments.

He says they're now more likely to use hand railings while going down stairs or offer their colleagues help with carrying heavy loads. When they don't stare down at smartphone screens, they notice how to avoid risks for themselves or others.

2. Barring smartphones could eliminate the need for costly upgrades

When looking at ways to improve its workplace safety culture, GM may have known that this decision to stop people from using smartphones while walking could be a cost saver by preventing accidents. Giving attention to smartphones could put people in harm's way.

A study showed that pedestrian road deaths have gone up 35 percent over the past decade. The research didn't suggest the percentage of time that smartphones were to blame for those fatalities. But, one South Korean city installed a system to help drivers and pedestrians become more aware of each other. And, the way it works suggests smartphones are typically in the equation.

Colored LED lights flicker on the pavement to alert drivers, but pedestrians get sent smartphone alerts via an app that warn them they're approaching traffic. One of the researchers involved in this project said a growing number of pedestrian accidents involve "smombies" — people distracted by their smartphones.

This system costs $13,250 per traffic crossing. With GM's option to eliminate the problem rather than implementing something new to solve the issue, it could keep costs down while prioritizing safety.

3. Having a reason for the rule promotes clarity

Smartphone use at work can boost productivity in some cases. For example, smartphones allow workers to stay mobile while communicating with clients. That option facilitates flexibility.

Plus, corporations can provide business-issued smartphones that are an identical make and model, then keep them all updated with approved apps. Doing that gives consistency and ensures employees don't use outdated operating systems or potentially unsafe apps.

The findings of a study involving Chinese workers and smartphones revealed that using the gadgets at work could increase a user's perceived job performance and workplace social capital. However, those positive effects decreased when people began to show signs of smartphone addiction.

That research emphasizes that smartphones are not hazardous in all cases, and can increase productivity — especially when used strategically and in moderation. GM likely understood that when making this rule. Remember, it didn't say employees couldn't use smartphones at all. It just stated that employees could not use smartphones as they walked.

The reason behind that decision was that getting distracted by smartphones could increase risky behavior. In a factory setting, it's especially easy to connect distractions with possible accidents. Heavy machinery and dangerous tasks pose enough hazards of their own without adding smartphone distractions. If you decide to restrict smartphone usage too, it's wise to do as GM did and clarify how implementing the rule will help.

4. New rules should fit into the overall safety culture

When you consider enforcing a new rule at work, think broadly about how it aligns with the company's safety goals. At GM, this rule about not using smartphones while walking is far from the only thing the company does to keep people safe.

One of GM's global policies is to schedule monthly safety walks where a safety review board takes a tour of a site building and looks for ways to make it safer. GM strongly encourages employees to attend, too. Then, every August, the company has a safety week, which is a company-wide review of safety achievements. During that period, people get recognized as "safety heroes" for going above and beyond in maintaining a safe workplace.

GM wants to keep people safe continually, not just sometimes. So, its smartphone restriction makes sense. If any upcoming rules you set are part of a broader effort to enhance safety, workers should be more likely to adopt them willingly.

A small change could make a big difference

GM's policy is one example of how one shift in user behavior could stimulate substantial progress. Consider examining the most dangerous habits your workers have and start from there when planning new safety procedures.