I apologize, but when I'm reading a customer's question, I look for a "?" to identify what the customer wants to know. There are no "?" in your question, so I didn't realize that you did ask a question: What I want to know is if the driver behind me jeopardized my life by denying me backward motion?
A: The obvious answer to your question is "of course -- yes," the driver behind you created a circumstance that could have jeopardized your life. The question, however, is not what is obvious, but rather what the law permits in terms of legal recourse.
There is a legal cause of action termed, "civil assault." This is the oldest of all wrongful injuries found in the law. It dates back to an ancient English case: Tuberville v. Savage, 1 Mod. Rep. 3, 86 Eng. Rep. 684 (1669).
In Illinois "[t]he tort of assault is defined as an  intentional,  unlawful  offer of corporal injury by force, or force unlawfully directed,  under such circumstances as to create a well-founded fear of imminent peril,  coupled with the present ability effectuate the attempt if not prevented." Benitez v. American Standard Circuits, Inc., 678 F.Supp.2d 745, 767 (N.D. Ill. 2010), citing Parrish v. Donahue, 443 N.E.2d 786, 788 (Ill. App. Ct. 1982).
If you could prove that the driver behind you (1) intended to prevent you from backing up your vehicle, so as to avoid injury, then all of the other elements of the assault fall into line. (2) There was an (2) unlawful, because intentionally creating circumstances that could cause another person a serious physical injury is clearly an attempted criminal assault; (3) there was offer of corporal/physical injury by force of impact by another vehicle; (4) you had a well-founded fear of imminent peril; and (5) the driver behind you had the ability to keep you from reversing your vehicle to avoid the impact.
Therefore, a civil assault was committed.
Similarly, there is the civil cause of action termed, "false imprisonment." This "tort" (civil wrong) is deceptive in its name, because "imprisonment" suggests a total physical confinement in a locked room. However, in Illinois, [t]he common law tort of false imprisonment is defined as an unlawful restraint of an individual's personal liberty or freedom of locomotion. (Johnson v. Jackson (1963), 43 Ill. App.2d 251, 258, 193 N.E.2d 485; Shelton v. Barry (1946), 328 Ill. App. 497, 506, 66 N.E.2d 697.) Imprisonment has been defined as "any unlawful exercise or show of force by which a person is compelled to remain where he does not wish to remain or to go where he does not wish to go." (McKendree v. Christy (1961), 29 Ill. App.2d 195, 199, 172 N.E. 2d 380.) In order for a false imprisonment to be present, there must be actual or legal intent to restrain. Campbell v. Kaczmarek (1976), 39 Ill. App.3d 465, 469, 350 N.E.2d 97.
Your facts actually suggest to me that false imprisonment may be a better cause of action, because the driver behind you, by blocking your means of escape, compelled you to remain where you were. And, that is prima facie (trans: on its face) false imprisonment.
So, you have two different legal claims against the other driver.
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