Exhibit 99.1

Marten Transport Announces First Quarter Results

MONDOVI, Wis., April 17, 2018 (GLOBE NEWSWIRE) -- Marten Transport, Ltd. (Nasdaq/GS:MRTN) today reported a 25.8% increase in net income to $10.3 million, or 19 cents per diluted share, for the first quarter ended March 31, 2018, from $8.2 million, or 15 cents per diluted share, for the first quarter of 2017.  The increase in earnings was primarily due to the reduction of Marten's federal income tax rate under the Tax Cuts and Jobs Act of 2017.

Operating revenue improved 8.0% to $187.0 million for the first quarter of 2018 from $173.2 million for the first quarter of 2017. Excluding fuel surcharges, operating revenue improved 4.7% to $163.8 million for the 2018 quarter from $156.6 million for the 2017 quarter. Fuel surcharge revenue increased to $23.1 million for the first quarter of 2018 from $16.6 million for the 2017 quarter.

Operating expenses as a percentage of operating revenue was 92.7% for the first quarter of 2018 and 92.0% for the first quarter of 2017. Operating expenses as a percentage of operating revenue, with both amounts net of fuel surcharges, was 91.7% for the first quarter of 2018 compared with 91.1% for the first quarter of 2017.

Chairman and Chief Executive Officer Randolph L. Marten said, “We continue to position our operations to capitalize on the strengthened freight environment. We improved our revenue excluding fuel surcharges in our Dedicated and Intermodal operations, our primary growth areas for this year, by 17.6% over the first quarter of 2017. We expect to deliver revenue and profitability growth throughout 2018 with increased compensation for our premium services, additional freight with existing and new customers, and our continued emphasis on cost controls.”

“Our agreements with a number of customers included a shift during the quarter between line haul and fuel surcharge revenue, which reduced our Dedicated and Truckload revenue, net of fuel surcharges, by $106 and $13 per tractor per week, while increasing our fuel surcharge revenue by the same amounts.”

Marten Transport, with headquarters in Mondovi, Wis., is one of the leading temperature-sensitive truckload carriers in the United States, specializing in transporting and distributing food and other consumer packaged goods that require a temperature-controlled or insulated environment. Marten’s dry freight services are expanding, with 1,376 dry trailers operating as of March 31, 2018. Marten offers service in the United States, Canada and Mexico, concentrating on expedited movements for high-volume customers. Marten’s common stock is traded on the Nasdaq Global Select Market under the symbol MRTN.

This press release contains certain statements that may be considered forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. These statements include our discussion of the Company’s prospects for future growth and by their nature involve substantial risks and uncertainties, and actual results may differ materially from those expressed in such forward-looking statements. Important factors known to the Company that could cause actual results to differ materially from those discussed in the forward-looking statements are discussed in Item 1A of the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. The Company undertakes no obligation to correct or update any forward-looking statements, whether as a result of new information, future events or otherwise.

CONTACTS: Tim Kohl, President, and Jim Hinnendael, Executive Vice President and Chief Financial Officer, of Marten Transport, Ltd., 715-926-4216.

MARTEN TRANSPORT, LTD.
CONSOLIDATED CONDENSED BALANCE SHEETS
(Unaudited)

(In thousands, except share information)	March 31, 2018			December 31, 2017
ASSETS
Current assets:
Cash and cash equivalents	$	10,398		$	15,791
Receivables:
Trade, net		82,090			74,886
Other		7,037			6,131
Prepaid expenses and other		19,186			19,810
Total current assets		118,711			116,618
Property and equipment:
Revenue equipment, buildings and land, office equipment and other		808,750			783,648
Accumulated depreciation		(217,558	)		(211,728	)
Net property and equipment		591,192			571,920
Other assets		2,062			1,865
Total assets	$	711,965		$	690,403
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Accounts payable and accrued liabilities	$	49,421		$	38,100
Insurance and claims accruals		25,414			26,177
Total current liabilities		74,835			64,277
Deferred income taxes		101,676			100,626
Total liabilities		176,511			164,903
Stockholders’ equity:
Preferred stock, $.01 par value per share; 2,000,000 shares authorized; no shares issued and outstanding		-			-
Common stock, $.01 par value per share; 96,000,000 shares authorized; 54,589,542 shares at March 31, 2018, and 54,533,455 shares at December 31, 2017, issued and outstanding		546			545
Additional paid-in capital		76,915			76,413
Retained earnings		457,993			448,542
Total stockholders’ equity		535,454			525,500
Total liabilities and stockholders’ equity	$	711,965		$	690,403

MARTEN TRANSPORT, LTD.
CONSOLIDATED CONDENSED STATEMENTS OF OPERATIONS
(Unaudited)

	Three Months
	Ended March 31,
(In thousands, except per share information)	2018			2017
Operating revenue	$	186,960		$	173,159
Operating expenses (income):
Salaries, wages and benefits		58,822			56,400
Purchased transportation		35,026			29,362
Fuel and fuel taxes		29,044			25,956
Supplies and maintenance		10,436			10,990
Depreciation		21,815			21,383
Operating taxes and licenses		2,287			2,247
Insurance and claims		10,290			8,914
Communications and utilities		1,683			1,581
Gain on disposition of revenue equipment		(1,211	)		(1,103	)
Other		5,174			3,491
Total operating expenses		173,366			159,221
Operating income		13,594			13,938
Other		(189	)		141
Income before income taxes		13,783			13,797
Income taxes expense		3,452			5,583
Net income	$	10,331		$	8,214
Basic earnings per common share	$	0.19		$	0.15
Diluted earnings per common share	$	0.19		$	0.15
Dividends declared per common share	$	0.025		$	0.015

MARTEN TRANSPORT, LTD.
SEGMENT INFORMATION
(Unaudited)

							Dollar			Percentage
							Change			Change
	Three Months						Three Months			Three Months
	Ended						Ended			Ended
	March 31,						March 31,			March 31,
(Dollars in thousands)	2018			2017			2018 vs. 2017			2018 vs. 2017
Operating revenue:
Truckload revenue, net of fuel surcharge revenue	$	80,216		$	84,811		$	(4,595	)		(5.4	)%
Truckload fuel surcharge revenue		12,801			10,847			1,954			18.0
Total Truckload revenue		93,017			95,658			(2,641	)		(2.8	)
Dedicated revenue, net of fuel surcharge revenue		42,364			36,899			5,465			14.8
Dedicated fuel surcharge revenue		6,469			3,378			3,091			91.5
Total Dedicated revenue		48,833			40,277			8,556			21.2
Intermodal revenue, net of fuel surcharge revenue		20,808			16,811			3,997			23.8
Intermodal fuel surcharge revenue		3,844			2,375			1,469			61.9
Total Intermodal revenue		24,652			19,186			5,466			28.5
Brokerage revenue		20,458			18,038			2,420			13.4
Total operating revenue	$	186,960		$	173,159		$	13,801			8.0	%
Operating income:
Truckload	$	6,815		$	5,974		$	841			14.1	%
Dedicated		2,488			4,487			(1,999	)		(44.6	)
Intermodal		2,978			2,149			829			38.6
Brokerage		1,313			1,328			(15	)		(1.1	)
Total operating income	$	13,594		$	13,938		$	(344	)		(2.5	)%
Operating ratio:
Truckload		92.7	%		93.8	%
Dedicated		94.9			88.9
Intermodal		87.9			88.8
Brokerage		93.6			92.6
Consolidated operating ratio		92.7	%		92.0	%

MARTEN TRANSPORT, LTD.
OPERATING STATISTICS
(Unaudited)

	Three Months
	Ended March 31,
	2018			2017
Truckload Segment:
Revenue (in thousands)	$	93,017		$	95,658
Average revenue, net of fuel surcharges, per tractor per week(1)	$	3,679		$	3,416
Average tractors(1)		1,696			1,931
Average miles per trip		603			615
Non-revenue miles percentage(2)		6.8	%		9.6	%
Total miles (in thousands)		40,582			46,060
Dedicated Segment:
Revenue (in thousands)	$	48,833		$	40,277
Average revenue, net of fuel surcharges, per tractor per week(1)	$	3,267		$	3,462
Average tractors(1)		1,009			829
Average miles per trip		297			299
Non-revenue miles percentage(2)		1.1	%		0.7	%
Total miles (in thousands)		21,135			18,579
Intermodal Segment:
Revenue (in thousands)	$	24,652		$	19,186
Loads		10,737			9,584
Average tractors		82			77
Brokerage Segment:
Revenue (in thousands)	$	20,458		$	18,038
Loads		11,889			13,354
At March 31, 2018 and March 31, 2017:
Total tractors(1)		2,785			2,827
Average age of company tractors (in years)		1.6			1.5
Total trailers		5,308			4,955
Average age of company trailers (in years)		2.6			2.8
Ratio of trailers to tractors(1)		1.9			1.8

	Three Months
	Ended March 31,
(In thousands)	2018			2017
Net cash provided by operating activities	$	23,182		$	37,674
Net cash (used for) investing activities		(27,392	)		(20,962	)
Net cash (used for) financing activities		(1,183	)		(8,135	)
Weighted average shares outstanding:
Basic		54,572			54,426
Diluted		55,095			54,738

(1)	Includes tractors driven by both company-employed drivers and independent contractors. Independent contractors provided 55 and 67 tractors as of March 31, 2018 and 2017, respectively.
(2)	Represents the percentage of miles for which the company is not compensated.