hit the gas

2014年のノーベル平和賞を受賞したパキスタンの教育活動家マララ・ユスフザイさん。2012年に下校中のスクールバスで頭部を銃撃され意識不明に陥ったものの，搬送された英バーミンガムの病院で奇跡的に命をとりとめたという経験を持っています。CNNの記事にあったその事件の様子について書かれた部分から英語表現を採り上げます。
gasという「ガソリン」という意味が想起されますが，その他に「(自動車の)アクセル(gas pedal)」（『プログレッシブ英和中辞典』小学館）という意味があり，hit the gasで「アクセルを踏む」「スピードを上げる」という意味があります。同辞書にはstep on the gas（スピードを速める）という用例を挙げられていました。（Koyamamoto）

Malala's journey from near death to the Nobel Peace Prize
(CNN) -- On Friday, Malala Yousafzai became the youngest recipient of the Nobel Peace Prize. But just a day earlier, she passed the two-year anniversary of the gruesome event that flung her and her cause onto the world stage -- the attempt on her life.
Malala was riding home from school on Tuesday, October 9, 2012.
Gunmen halted the van ferrying her through her native Swat Valley, one of the most conservative regions in Pakistan. They demanded that other girls in the vehicle identify her. Malala had faced frequent death threats in the past.
She was pointed out. At least one gunman opened fire, wounding three girls. Two suffered nonlethal injuries, but bullets struck Malala in the head and neck.
The bus driver hit the gas. The assailants got away.
Malala was left in critical condition. An uncle described her as having excruciating pain and being unable to stop moving her arms and legs.
http://edition.cnn.com/2014/10/10/world/asia/pakistan-malala-odyssey/index.html?hpt=hp_c1