Jamaican Bus Ride describes the experience of riding on a densely-packed bus, focusing on the people inside, their possessions and behaviors, and the nature of the trip itself, ending with an exclamation that the driver may be drunk.
The poem is composed as prose, and is generally structured so that each separate statement, idea, or description is given its own line:
The four very large baskets on the floor
are in everybody's way,
as the conductor points out
loudly, often, but in vain.
This has the effect of drawing attention to each element and painting a denser and more colorful picture, and possibly enhancing the chance to surprise the reader as well (one element of which is described below).
A few pauses separate elements of action; the poem begins in an in media res manner, with the author already on the bus, describing the atmosphere. There is a brief pause to focus on two "quadroon (mixed-race) dandies" arguing with each other over something ridiculous, perhaps to give a sense of the eccentric personalities on the bus, and to tie it into Jamaica's history as a British colony. This introductory section is distinguished from the other two-thirds of the poem, describing the difficult of cramming more people onto the bus, and the bus taking off at extreme speed. The relatively calm pacing and order of the poem seems to be at odds with the environment and actions it describes, perhaps implying that the author is of an exceptionally stable frame of mind.
Figures of speech the phrase "hell-for-leather", implying top speed, and the mention of "invisible crannies" - which are surely not actually invisible, but instead an implication of how very small and previous inconceivable a space someone has managed to wedge themselves into.
Some subtleties include the reference to people entering and exiting through the wrong doors; this is not commented upon in a critical tone, implying that the labeling of the doors is largely irrelevant, and that basic operational policies, like limiting the occupancy of the bus, are, paradoxically, ignored, rendering any attempted regulations useless.
There is also the mention of the driver "fortifying himself" (another figure of speech, meaning drinking alcohol). The subtlety here is that it is hoped the driver has not been drinking, but the following line states "with more than four rums". In America, we might be shocked to learn that a driver has had even one, but the subtlety implied here is that drinking is common, and that it's only at or after four that a serious problem arises. This is similar to the issue of the entrance and exit doors; there is a certain degree of lawlessness to the bus, but one which is oddly closer to and more in tune with reality than the artificiality of an all-or-nothing approach to correct and incorrect actions.