DETROIT — The F-150 redesign that Ford Motor Co. plans to unveil this week isn’t as risky as the switch to an aluminum body for the current generation. But the new pickup nonetheless will determine the automaker’s fortunes in a segment that’s increasingly volatile and soon to be invaded by electric vehicle makers.

The gamble Ford took in switching to a more expensive material on its most important vehicle has largely paid off, though perhaps less conspicuously than Ford had hoped.

Since the pickup was redesigned in 2014, sales, market share and average transaction prices have risen, and studies have shown that repair and insurance costs — a major question mark at launch — have largely remained flat. The rest of the industry, however, declined to follow Ford’s aluminum gambit, choosing other routes to reduce weight and improve fuel efficiency.

Still, Ford sold more pickups in 2018 than any other year besides 2001 and 2004. It ended 2018 with its biggest-ever lead over the No. 2 vehicle and comfortably retained its crown last year, even as Fiat Chrysler’s Ram leapfrogged the Chevrolet Silverado.

In the 14th-generation F-150, scheduled to go on sale this year, Ford faces a new challenge: launch a redesigned model without the headline-grabbing attention or industry-rattling impact of a wholesale material switch while continuing to pace an intensely competitive field.

“We’re looking at every inch of the truck as we come out with the next generation,” Todd Eckert, Ford’s truck group marketing manager, told Automotive News.

“We still see the need for capability, for durability and reliability. People are still buying trucks for purpose-built reasons. We know we need to continue to deliver for