This highway was built during World War II to help the American military transport equipment to and from Alaska.
Give your car a good mechanical evaluation before you attempt this trip. Sign up for roadside service such as AAA/CAA, but verify that they will cover the entire cost of towing you long distances. Many services will cover only a few hundred dollars, which is not sufficient.
You should carry enough emergency supplies to last yourself one or two nights. Most of the highway has NO mobile telephone service. The nearest tow truck can be 1000 km (621 mi) away. It is even more important to carry emergency supplies in winter to avoid hypothermia and death. At the very least, bring food, water, blankets, a first-aid kit, and spare tires. Wintertime temperatures can dive as low as -40 C / -40 F. Bug repellent may be very nice to have in the summer.
For winter driving, you need winter or all-weather tires and low-weight oil (5W30 or as recommended by your manufacturer).
Be sure to verify that you have the appropriate entry documents for Canada or the United States, depending on your direction. Note that Canadian immigration can request that you show proof of enough funds to cover your trip and an emergency. A bank/ATM receipt, a few credit cards, traveler's checks, or cash will suffice. They will refuse entry to Canada if you do not demonstrate enough funding for your trip.
Gas (petrol) stations in this part of Canada are frequently not 24 h, especially in winter, and most of them do not have a pay-at-the-pump mechanism. Many stations have very long distances between them. You should keep your tank as full as you can and be prepared to wait for a station to open if you arrive in the middle of the night. Some newer pumps in Canada operate with the credit card "chip" system, the pumps in Alaska, (US) still only use the "swipe" credit card system.
Cellphone coverage is very sparse, although every Yukon community along the highway has cell service in the vicinity. Do not count on using your cellphone in an emergency as the distances between areas can be well over an hour or two.
The highway may be in various states of repair. Be prepared to wait long periods as road crews continue to maintain the road. Winter frost is extremely hard on the roads. Do not be surprised to see deep fissures across the highway.
Getting to the Alaska Highway is no small feat in itself. It starts in Dawson Creek in Northern British Columbia. You can get to Dawson Creek either by driving north from Southern British Columbia through Prince George or by driving Northwest from Edmonton.
Whitehorse is the largest city along the highway, until you reach Fairbanks at the end. The Whitehorse airport (YXY) is served by Air Canada , Air North , and First Air . Nearly all of the flights are to or from Vancouver. There is also summertime nonstop or one-stop service to Frankfurt, Germany, via Condor airlines .
Dawson Creek does have a regional airport that is served by Central Mountain Air  and Hawkair . However, it would not be advisable to try and rent a car in Dawson Creek for this long drive. It would be more reasonable to rent a car in Edmonton. Another alternative would be to rent an RV for this drive. However, this is usually quite expensive and after the cost of gas, probably more expensive than staying in a hotel every night. However, with the sparse provision of hotels, having an RV can be more convenient.
Greyhound serves the highway and terminates in Whitehorse. GreyhoundLimited bus service is available between Whitehorse, Anchorage, and Fairbanks as well as points along these routes. Be sure to reserve in advance and allow some flexibility in your schedule as buses may be rescheduled based on demand. Visit Alaska Direct Bus Lines website  for pricing and schedules.
The only real possible way of doing this trip is driving. Many travellers do this trip with a Recreational Vehicle (RV).
Although Canada almost exclusively uses the metric system, most points along the Alaska Highway can be still identified by mileage:
Remember that you will have more than 20 h of sunlight during the summer months and less than 5 h of sunlight in the middle of winter.
Highway 37 goes North from Terrace and joins the Alaska Highway near the BC-Yukon Border.
Rather than going west from Whitehorse, you can go north along along the Klondike Highway to the Historic Gold Rush town of Dawson City then take the Top of the World Highway to the Alaska border at Poker Creek and then Take the Taylor Highway back to the Alaska Highway. This road is seasonable.
Follow all advice in the Prepare section.