SOUTHFIELD, Mich. — Self-driving cars (SDC) that include driver control are expected to hit highways around the globe before 2025. Self-driving “only” cars are anticipated to hit the market around 2030, according to an emerging technologies study on autonomous cars from Polk’s IHS Automotive.

In the study, “Emerging Technologies: Autonomous Cars — Not If, But When,” IHS Automotive forecasts total worldwide sales of self-driving cars will grow from nearly 230,000 in 2025 to 11.8 million in 2035 — seven million of which will be SDCs with both driver control and autonomous control, while 4.8 million will be autonomous control only. In all, there should be nearly 54 million self-driving cars in use globally by 2035, according to the study.

The price premium for the SDC electronics technology will add between $7,000 and $10,000 to a car’s sticker price in 2025, a figure that will drop to around $5,000 in 2030 and about $3,000 in 2035, when no driver controls are available.

“There are several benefits from self-driving cars to society, drivers and pedestrians,” said Egil Juliussen, principal analyst for infotainment and autonomous driver assisted systems at IHS Automotive. Juliussen co-authored the study with IHS Automotive senior ADAS analyst Jeremy Carlson.

“Accident rates will plunge to near zero for SDCs, although other cars will crash into SDCs, but as the market share of SDCs on the highway grows, overall accident rates will decline steadily,” Juliussen added. “Traffic congestion and air pollution per car should also decline because SDCs can be programmed to be more efficient in their driving patterns.”

The study also noted some potential barriers to SDC deployment and two major technology risks: software reliability and cyber security. The barriers include implementation of a legal framework for self-driving cars and establishment of government rules and regulations.

Several automakers have said publicly they will have autonomous cars by 2020, or earlier, the study noted. Autonomous car technology is already affecting driver assist systems such as adaptive cruise control, lane keep assist and collision mitigating brake systems. Additionally, the IHS study says the first group of autonomous cars will have so-called Level 3 capability — limited self-driving that enables the driver to cede full control of all safety-critical functions under certain traffic and environmental conditions and includes auto pilot for highway travel and parking. Coming later in the decade will be SDCs with Level 4 capability — self-driving but with human controls.

North America is forecasted to account for 29 percent of worldwide sales of self-driving cars with human controls (level 4) and self-driving-only cars (level 5) in 2035, or nearly 3.5 million vehicles. China will capture the second largest share at 24 percent, or more than 2.8 million units, while Western Europe will account for 20 percent of the total, 2.4 million vehicles.