This question examines four characteristics of big data.

The characteristics of big data can be represented by "4V", that is, the four V's of volume, type, value and speed summarize the characteristics of big data.

(1) The amount of data is huge.

(2) Diversity of data types.

(3) Low value density.

(4) High timeliness (speed)

The real-time road traffic situation of smart transportation reflects the high timeliness of big data technology, so this question chooses D.

Big data technology system

(1) data preparation link

(2) Data storage and management.

(3) Calculation and processing links

(4) data analysis

(5) Knowledge display link