BOT:
"Build-Operate-Transfer mode

Dual-track:
railway with two main lanes, namely upper lane and lower lane

Engineering method:
An integrated construction method with application of systematic construction principles to combine advanced technology and scientific management, under which certain engineering practices will be applied to the construction in line with technology.

Main lane:
track connecting and passing through the stations

PPP:
"Private Build-Public Lease-Private Operate mode

TOT:
"Transfer-Operate-Transfer mode

Traffic density:
refers to the traffic volume carried by a particular means of transportation during a given period through one kilometer of a specific section of a transportation route

Turnout:
a component used for changing the route of a train where a single track splits into two tracks. Turnout is applied in railway tracks.

Upstream, Middle-stream and Downstream:
The three business segments in the industry value chain of construction industry as divided by business process. The upstream business primary consists of project consulting and design business, project development business and project construction management business; the middle-stream mainly refers to the construction work of projects; the downstream business primarily includes the operation, management and maintenance of various infrastructure facilities.