Bobbyben, I think the article is referring more to engineering...

Bobbyben, I think the article is referring more to engineering services and road maintenance like resurfacing. But I may be wrong.
TTI is involved more with lighting and signage of major roads, motorways, residential areas like parks and minor roads. It is also involved in traffic light technology.
You can Google "Aldrige Traffic Systems". It manufactures, designs and installs traffic signals, emergency telephones, portable roadside technology and road lighting products and is a subsidiary arm of TTI.
QTC is also a subsidiary co of TTI. It manufactures traffic controllers which coordinate traffic systems and control traffic flow in major cities.
Recent contract wins for TTI involve LED lighting technology which requires lower power consumption, less maintenance and longer lifecycles.
I hope it answers your question.