Often while constructing my travel, I try to add an extra segment in the intinerary. Helps maintain that elite status that counts segments (CO) or allows an hour or two for lunch with a friend in the connecting city. Sabre (deceased since summer 1999) used to list the permitted connecting cities. No longer. I can get the detailed fare rules from travelocity.com, but the cities are not listed.
Does anyone know of a reservation system available to the public via the web that provides this vital information?
A routing of STL-MEM-MCI-DTW-CLT prices the same as STL-DTW-CLT; but, I met up with friends not seen in a while.
Thanks in advance.

Don't know of a site to help but would also like to know. In Canada, we are getting more rules/charges for connections. They are adding a 15 or 7.50 CAD ($10 or $5 US) fee for every connection.

Some cheaper international fares only allow one on-line connection preventing abuse of the 24 hour stopover rule on international flights that could otherwise be used to more cheaply help one hop across the country doing business in a new city every day and have a weekend vacation overseas at the end of that week.

Expedia used to have this feature, but seems to have dropped it as recently as a few weeks ago. What a shame. It was a great feature, precisely for the reason you cite, Mr. Airport

I don't know of any websites that do this, sorry.

If anyone can produce one, I'd be curious to explore it.

Doesn't this information sometimes come up in the rule display on Travelocity? Or I am getting this confused with the co-terminal origin cities (ie same fare basis from LGA/EWR)?

Expedia and Travelocity shows only those co-terminal cities. {This info is helpful when you want to purchase a cheapie ticket to BWI but the fare rule allows you to standby to DCA or IAD.} The fare rules do disclose how many online connections are permitted {sometimes unlimited but most often 4 in each direction} which helps in the construction of a routing.

I realize you asked for a site that is available to the public, but I wonder, for complex questions such as this, why not contact a good travel agent? You could get your answer in about two minutes.

It's not really that complex of a question. Expedia used to provide this in the fare rules as par for the course. It's curious why that's not so anymore.

Of course, you could always call the carrier for the info.

Blonde,

With more and more US airports also charging PFCs, as well as with the new segment charge by the US government (versus the straight tax percentage on the total ticket price) it may well cost a significant amount of extra money to fly 7 segments between two cities.

Sometimes, in doing some searches on the NW site, I've come across it offering me a PHX-DTW leg as PHX-DTW-ATL-DTW. It's only been less than $10 more (for PFCs, I imagine) and about 6-7 hours' time and would be worth an extra 1,200 or so base miles. I checked for later in the year recently, and that didn't show up, though.

Try using the "multiple destinations" sections of the search engines.Input logical connections. Assume that you can travel 150% of the non-stop distance. For instance, EWR-SEA(~2400 miles OW) can be done EWR-IAH-SEA on CO- ~3300 miles). About a month ago I got a $400 RT by playing with this on NW as follows: EWR-DTW-IAH-MSP-IAH-SEA. Note that this cannot be done on the return becasue ofthe time differences.

Vulcan-
Most times they do not permit transiting the same airport more than once while traveling in one direction of the ticket. Exception: on the direct NW STL-IAH flight stops in MEM. Since MEM is not shown in the itinerary, you can go STL-IAH-MEM-PHL per the ticket but in reality fly STL-MEM-IAH-MEM-PHL.
Motnot -
If you are building mileage and/or segments, and you have the time to fly, a couple extra segments for $10 is not shabby. There are times when time is limited, but on the those getaway weekends designated for a mileage run, a couple extra airports are sometimes welcomed. Besides, visiting friends, albeit only 35 minutes, is satisfying.
fare rules from travelocity.com, but the cities are not listed.

Did you see the NW promo for triple miles when connecting through Memphis? Just thought I would throw it in since you mentioned a routing through there. When I checked a routing online to see if I could take advantage of a unique trip to take advantage of the bonus, the only difference in the price was the PAX FAC charge. I know this doesn't answer your question and the post about calling the airline is as reliable as checking unique fares and getting six quotes on six different calls.

I also recall a trip to Australia a few years ago on Quantas that allowed us to add a stopover for an additional $150. We did New Zealand for a week, another couple did Fiji and the other three couples did Hawaii...well overdue for that trip again! Happy flying!!!