The “American Idol” locomotive was in full throttle last week, occupying one-third of Fox’s schedule as the net routed its rivals in key demos.

Three nights of “American Idol” finished well ahead of anything else in primetime among adults 18-49, with ABC’s “Modern Family” and MTV’s “Jersey Shore” — the top non-“Idol” skeins of the frame — settling for half of what the music talent show did on its top night.

Fox aired 90-minute segs of “Idol” on Tuesday and Wednesday, leading into a pair of under-performing first-year comedies, “Raising Hope” and “Traffic Light,” respectively. Both laffers hit season highs and will now look to bring back some of those viewers when they proceed without the “Idol” support.

Another first-year Fox comedy, “Bob’s Burgers,” has performed passably in what has been a soft midseason for new half-hours. Among the more recent additions, CBS’ “Mad Love” is doing OK on Monday, while NBC’s “Perfect Couples” and ABC’s “Mr. Sunshine” are struggling.Overall, according to Nielsen estimates for the week of Feb. 28-March 6, Fox led in adults 18-49 with a 4.0 rating/12 share, followed by CBS (2.3/7), ABC (2.0/6), NBC (1.6/5), Univision (1.4/4) and top cabler USA (0.9/3).

Fox also dominated in adults 25-54 (4.7/12 to 3.2/8 for runner-up CBS) as well as total viewers (11.6 million to 10 million for the Eye).

“American Idol” rolled with performances segs on Tuesday (7.6/21 in 18-49, 21.39m) and Wednesday (7.8/22, 22.76m) and then posted its best numbers with Thursday’s two-hour results show (8.2/24, 25.26m), which delivered the top averages on the night for any net (excluding sports) in four years.

In a week when “Glee” was pre-empted by “Idol,” Monday drama “House” was the net’s top scripted program (3.8/11, 11.01m).

As for the young comedies, Tuesday’s “Raising Hope” fared best (3.3/9, 8.68m), while “Traffic Light” did a 2.8/8 in the demo and drew 7.32 million viewers overall. On Sunday, “Bob’s Burgers” (2.2/6, 4.91m) sagged between “The Simpsons” (2.8/8, 6.13m) and “Family Guy” (3.1/8, 6.33m).

CBS was led by “NCIS” (3.8/1, 19.21m) and “Criminal Minds” (3.6/10, 14.37m), which held up well opposite Fox’s “Idol.” After “Criminal” on Wednesday, spinoff “Suspect Behavior” (2.6/8, 10.36m) led its hour and was up slightly week to week (opposite a repeat of NBC’s “Law and Order: SVU”).

At ABC, “Modern Family” remains a standout (4.1/11 in 18-49, 10.11m) — the No. 1 scripted show in 18-49, and one that likely grew substantially in same-week DVR playback since it again opposed “American Idol.” (Numbers released this week for Feb. 16, when it also faced “Idol,” showed “Modern Family” gaining a record 1.9 ratings points from its same-night to full-week 18-49 score, going from a 4.3 to a 6.2.)

NBC didn’t have a whole lot going, led by two-hour reality shows “Celebrity Apprentice” (2.8/7 in 18-49, 7.93m in its premiere) — its lone rep among the week’s top 25 shows — and “The Biggest Loser” (2.4/7, 7.06m). Unscripted skein “America’s Next Great Restaurant” opened modestly Sunday (1.6/4, 4.59m).

And at CW, it was slow going for the second week of “Shedding for the Wedding” (0.4/1, 1.07m), which followed a below-average “Top Model” (0.9/3, 1.96m).

USA led cable nets, as “WWE Raw” was again above average (2.2/7 in 18-49, 5.61m for its 10 p.m. hour).

MTV’s “Jersey Shore” continues to shine (4.1/11, 7.77m), finishing well ahead of the next top-rated entertainment shows on cable: MTV’s “Teen Mom” (1.9/5, 3.43m) and Comedy Central’s spec “Daniel Tosh: Happy Thoughts” (1.9/5, 3.21m).

The fifth-season premiere of Lifetime’s “Army Wives” (1.4/3, 4.23m) was up by double-digit percentages in key demos over last year’s bow while growing by 27% in total viewers.

It was actually a busy night for shows with “Wives” in their titles: In addition to “Army Wives” and ABC vet “Desperate Housewives” (3.4/8, 11.35m), there was VH1’s “Basketball Wives” (series high 1.2/3. 2.28m) and Bravo’s “Real Housewives of Orange County” (1.1/3, 2.05m).

Also: A&E’s Sunday drama “Breakout Kings” set a record for a series premiere on the net (1.2/3, 2.81m); Discovery’s premiere of “Sons of Guns” (0.9/3 in 18-49, 2.20m) was Wednesday’s No. 1 cable program in all key male demos; and Food Network’s “Chopped All-Stars” (1.3/3, 3.21m) hit a series high Sunday.