Automakers are rolling out safety advances three times faster than they did in the mid-1990s, making vehicles more crashworthy, according to recent studies by the Highway Loss Data Institute.

However, the Institute notes that new safety features can still take decades to make it into the broader fleet on the nation’s roadways.

To determine how well manufacturers are working to improve safety, the HLDI analysis explored four of the Insurance Institute for Highway Safety's ratings evaluations: moderate overlap front, side, roof strength and driver-side small overlap front.

The findings show that the percentage of tested vehicles that earn a good rating in the oldest test — the moderate overlap which was introduced in 1995 — has increased an average of 2% per year.

Moreover, for the newer driver-side small overlap test the rate of increase to good scores has accelerated 6% per year.

While this is good news for drivers of brand-new vehicles, it still takes many years to impact the entire fleet of cars on the road. Simply put, many motorists hold onto older vehicles despite safety improvements.

For example, even 23 years after its introduction, only 64% of all U.S. vehicles have earned a good rating in the moderate overlap test. Moreover, six years after the introduction of the driver-side small overlap test, just 14% of the fleet garners a good rating in that evaluation.

In another analysis, HLDI researchers looked at the estimated availability and installation of rear cameras, rear parking sensors, blind spot monitoring, forward collision warning, front automatic emergency braking, lane departure warning and curve-adaptive headlights from the years these features were introduced through calendar year 2050.

With the exception of curve-adaptive headlights, these features have been filtering into the broader fleet at a faster rate in recent years than happened earlier. 

Noteworthy, two features that are required by government mandate or slated for universal adoption by a voluntary manufacturer commitment are spreading even faster since those measures were announced.

Consider rear cameras, for example. Introduced in model year 2002, they are now required on all new vehicles, and are expected to be installed on more than half of all registered vehicles by 2023.

What’s more, in 2018, approximately 5% of all U.S. vehicles were equipped with front autobrake. But experts expect that number to increase nearly fivefold to 24% in 2023.