many, if not most, "lay members" (not rabbis or prayer leaders) of conservative synagogues in north america do not follow these laws. progressive judaism, including reform judaism, does not accept jewish law as binding. these jews may rest on shabbat, but are not usually strict about not doing "melacha" or "shevut." they may even add practices not allowed under orthodox jewish law that they think improves their celebration of shabbat. for example, they may drive to synagogue on shabbat, or may use musical instruments on shabbat. orthodox judaism does not allow either of those actions on shabbat.