My thought on the idea of a streetcar was somewhat similar to Keithp's - but I kept the lines I thought of away from Spring Garden Road. Mainly because the street is congested enough as is with deliveries, cars, buses...it would be a different story if it became a transit only street, but for now I kept my ideas off of it.
I looked at using streets that were close by that had far less traffic, so that locating a streetcar as embeded rails wouldn't be a big disruption. So when I thought of the SGR area - I thought of Morris Street/University Avenue. It's only a block or two away, so it's a quick walk.
I came up with 4 different lines, which can be seen on this
The two lines that are Halifax Peninsula specific are: (a) the Agricola loop - starting at the NSCC campus on leeds, following Agricola and Cogswell into downtown along Hollis to the train station and down Barrington, under the railway tracks and then back into downtown from the Pier 21/Seaport area along Lower Water and back up Cogswell/Agricola to the Hydrostone and then along Devonshire to the NSCC.
(b) Starting at Mumford Terminal, under the parking lots of HSC, along Connaught to Windsor. Along Windsor to Cunard where it would then share the same line as route (a) through the downtown core until reaching Morris Street. Then line (b) would branch off at Morris and head along right up University and turning left onto Robie, would end at St. Mary's. The line would then reverse and back track along Morris until reaching the common outbound line along Lower Water Street and reverse the inbound route ending at Mumford.
I won't describe the other two lines, you can look at them from the map. My idea had been to have a shared segment in the downtown so that you could have a higher frequency of service in the downtown core (to service the office people during the lunch time rush) but also minimize car traffic impact as much as possible (I don't think that can be avoided with Lower Water and Hollis Street, but with the other streets it could). The other main goal was to use the Streetcar as a catalyst to encourage redevelopment in areas where it could be done (such as along Windsor Street, Agricola, the Hydrostone, etc). Finally, the other main rationale was to put major destinations along the routes that would generate useage. It's one thing to build a streetcar, but if it doesn't serve anything important - whose going to use it? If you take it places people want/need to go too, you create the greater possibility of success.