I ride everything from a recumbent trike to a s/s chopper on the main roads, no great difference really a bike is generally a lot slower than a car so a few kph slower isn't a great difference, and I doubt your cruiser is wider than my trike
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If you feel confident doing so go for it.
Ps. If the take off speed is a concern, a cheap low powered electric geared hub can, with pedalling allow you to blow any "real bike" and a lot of cars off at the lights