As reported in the parsha sheet “Divrei Siach,” R’ Chaim Kanievsky was asked whether it is preferable to take a longer route walking to one’s destination on Shabbos to avoid seeing car traffic or whether it doesn’t matter, as the cars are being driven by non-Jews. R’ Chaim answered that it is better to avoid seeing the cars. His proof is from Brachos 53, where the gemara says that a candle lit by a non-Jew on Shabbos is not usable for havdalah, but a candle lit for a sick person is usable because it was lit b’heter. You see from the gemara that even though a non-Jew has no mitzvah to keep Shabbos, his/her lighting of the candle is still considered an act of chilul Shabbos which renders the candle unfit for use.
When the Chofetz Chaim visited the big city of Warsaw and saw chilul Shabbos the first time, he trembled. The next time he saw it, he felt less moved. The Chofetz Chaim remarked that from his own experience he now sees how quickly we become desensitized to aveiros. You may not be the one driving the car on Shabbos, but seeing the chilul Shabbos, even if done by an aku”m, has a tremendous effect on one’s appreciation for the holiness of Shabbos kodesh.
The issue the question posed to R' Chaim raises is already discussed R’ Yosef Engel in a number of places. There are Achronim who view all time-centric issurim as being issurei gavra. For example, they argue that food on Yom Kippur is not inherently assur in the same that bacon is assur. Bacon is a cheftza of issur; food on Yom Kippur is a cheftza of heter, just there is an issur that prevents the individual from eating. R’ Yosef Engel is not convinced, and he uses this gemara from Brachos 53 to prove his point. A non-Jew has no chovas ha’gavra to observe Shabbos. Nonetheless, the melacha done by him/her is considered a cheftza of issur, and therefore the candle lit by the aku"m can’t be used for havdalah. In the case of the car traffic, again, there is no issur gavra obligating the non-Jew to keep Shabbos, but the melacha done may still be a cheftza shel issur.
One could argue that perhaps Brachos 53 is a unique din in hilchos brachos and not indicative of the nature of issurei Shabbos. However, what I think is the stronger objection is that this approach can lead to a tartei-d’sasrei contradiction in terms. A non-Jew is not only not obligated to observe Shabbos; he/she is prohibited from observing Shabbos. Let’s say John Smith has not done any melachah this Saturday. On the one hand his lighting a fire under those circumsances would be considered a mitzvah, because otherwise he would be in violation of the ben-noach issur of shemiras Shabbos, but at the same time the same lighting would be a cheftza shel issur. How can the same act be both? R Yosef Engel therefore suggests that this may be a unique din by havarah. A non-Jew who needs to do a melacha to avoid chilul Shabbos should choose something other than lighting a fire, as that act is classified as chilul Shabbos for everyone, Jew and non-Jew alike.
The Pireki D”R’ Eliezer writes that when Adam haRishon saw fire on Motzei Shabbos he said the bracha of borei me’orei ha’eish. The implication is that Adam haRishon did not light a fire on Shabbos itself. R’ Yosef Engel in Beis ha’Otzar writes that this does not prove that Adam observed the Torah before it was given as the Avos did. The Midrash is speaking about the melacha of lighting a fire, and that melacha in particular may be categorically classified as chilul Shabbos no matter who is doing the lighting.