2017’s Northern Tier is a standalone post-apocalyptic novel by David Axel Kurtz.
Two centuries after nuclear war and the collapse of petroleum-based civilization, North America is divided between several nations: Nova Scotia et Hibernia, Minnetonka, Central, Two Crowns, and others. Trade between nations has become slow and difficult, creating a niche for couriers who are willing to brave the dangers of the open road to deliver small, valuable packages quickly. The cycers, bicycle couriers like Slip, fill this niche.
Slip is a survivor, smart and cautious enough to survive a lifestyle that kills most cycers young. But this time, one moment of bad judgment on her part may doom not just Slip, but the entire cycer way of life.