Segment Information (Details) $ in Thousands	3 Months Ended
Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments	2
Revenue	$ 3,372	$ 3,010
Gross profit	2,595	2,563
Amortization of intangible assets	150	111
Intangible assets	3,586	3,440
Intersection [Member]
Segment Reporting Information [Line Items]
Revenue	2,072	2,417
Gross profit	1,792	2,186
Amortization of intangible assets	92	92
Intangible assets	2,018	2,385
Highway [Member]
Segment Reporting Information [Line Items]
Revenue	1,300	593
Gross profit	803	377
Amortization of intangible assets	58	19
Intangible assets	$ 1,568	$ 1,055

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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